The described evasion relies on preventing the IDS from correctly reassembling packets, which points directly to packet fragmentation. In fragmentation-based evasion, the attacker breaks the probe payload into multiple IP fragments. Some IDS sensors-especially if misconfigured, overloaded, or using limited reassembly logic-may fail to fully reconstruct the original packet stream, causing the malicious or suspicious content to evade signature matching and detection. Meanwhile, the target host (or a downstream device) may correctly reassemble the fragments and process the probe normally. This mismatch between what the IDS "sees" and what the target ultimately receives is the core concept behind fragmentation evasion.
The scenario explicitly says "IDS devices are unable to reassemble the packets correctly," which is essentially the textbook rationale for fragmentation as an IDS evasion method. Attackers may vary fragment size, overlap fragments, or manipulate offsets to stress or confuse reassembly engines. Even when modern IDS systems support reassembly, fragmentation can still be used to reduce detection reliability if sensors are under resource pressure or if traffic normalization is not enforced.
Why the other options don't match:
Source routing (B) attempts to influence the path packets take through the network; it does not inherently prevent IDS reassembly.
Decoy scanning (C) floods the target/IDS with scans from multiple spoofed addresses to obscure the true scanner source. This is about attribution noise, not packet reassembly failure.
IP spoofing (D) for scanning can disguise origin, but it does not inherently cause IDS reassembly problems.
Therefore, Maria is applying A. Packet Fragmentation.

Cloud-based detection collects data from protected systems and performs malware analysis in the provider's cloud environment rather than relying solely on local endpoint analysis.

https://en.wikipedia.org/wiki/MAC_filtering
MAC filtering is a security method based on access control. Each address is assigned a 48-bit address, which is used to determine whether we can access a network or not. It helps in listing a set of allowed devices that you need on your Wi-Fi and the list of denied devices that you don't want on your Wi-Fi. It helps in preventing unwanted access to the network. In a way, we can blacklist or white list certain computers based on their MAC address. We can configure the filter to allow connection only to those devices included in the white list. White lists provide greater security than blacklists because the router grants access only to selected devices.
It is used on enterprise wireless networks having multiple access points to prevent clients from communicating with each other. The access point can be configured only to allow clients to talk to the default gateway, but not other wireless clients. It increases the efficiency of access to a network.
The router allows configuring a list of allowed MAC addresses in its web interface, allowing you to choose which devices can connect to your network. The router has several functions designed to improve the network's security, but not all are useful. Media access control may seem advantageous, but there are certain flaws.
On a wireless network, the device with the proper credentials such as SSID and password can authenticate with the router and join the network, which gets an IP address and access to the internet and any shared resources.
MAC address filtering adds an extra layer of security that checks the device's MAC address against a list of agreed addresses. If the client's address matches one on the router's list, access is granted; otherwise, it doesn' t join the network.

The correct answer is Checks for outdated versions of over 1,250 servers. In CEH vulnerability assessment coverage, Nessus Essentials is presented as a vulnerability scanning solution that can assess a wide variety of technologies, including operating systems, web servers, databases, network devices, and virtualized environments. Its core role is identifying weaknesses, missing patches, insecure configurations, and exposure conditions across supported platforms. The option about checking outdated versions across a very broad range of server technologies best reflects that scanner-oriented capability. Patch management is not the primary function of Nessus Essentials, because it identifies vulnerabilities rather than directly managing patch deployment. Agent-based detection may be used in some security products, but that is not the defining capability highlighted in this CEH-style framing. High-speed asset discovery is a feature associated more strongly with specialized discovery platforms, whereas Nessus is centered on vulnerability enumeration and assessment. CEH study material emphasizes understanding the purpose of common security tools, and Nessus is generally classified as a scanner that detects outdated software versions and known vulnerabilities so remediation can be prioritized across the environment. That is why option B is the most accurate fit.