Explanation
Using an out-of-band access method is the best way to prevent unauthorized access to the legacy switches that do not support cryptographic functions. Out-of-band access is a method of accessing a network device through a dedicated channel that is separate from the main network traffic. Out-of-band access can use physical connections such as serial console ports or dial-up modems, or logical connections such as VPNs or firewalls.
Out-of-band access provides more security and reliability than in-band access, which uses the same network as the data traffic and may be vulnerable to attacks or failures. References:
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/fundamentals/configuration/15mt/fundamentals-15-mt-book/c

A default gateway is a device that routes traffic from one network to another network, such as the Internet.
A default gateway is usually configured on each host device to specify the IP address of the router that connects the host's network to other networks.
In this case, the user's device and the destination device are on different networks (192.168.1.0/24 and 192.168.2.0/24), so the user needs to configure a default gateway on their device to reach the destination device. Reference: https://partners.comptia.org/docs/default-source/resources/comptia-network-n10-008-exam-objectives-(2-0), https://www.techopedia.com/definition/25761/default-gateway

A /30 subnet is the smallest possible subnet that can be used for a point-to-point configuration between two routers. A /30 subnet has only two usable host addresses, one for each router, and a network address and a broadcast address. A /30 subnet conserves IP space by minimizing the number of wasted addresses. A /24, /26, or /28 subnet would have more usable host addresses than needed for a point-to-point configuration and would waste IP space.
Reference:
Routing Technologies - N10-008 CompTIA Network+ : 2.21
CompTIA Network+ Certification Exam Objectives, page 10

Explanation
IaaS stands for Infrastructure as a Service, which is a cloud computing model that provides virtualized computing resources such as servers, storage, and networking over the Internet. When implementing IaaS, the network technician should consider the server hardware requirements, such as CPU, RAM, disk space, and network bandwidth, that are needed to run the applications and services on the cloud. The other options are not relevant to IaaS, as they are either handled by the cloud provider or by the end-user. References:
https://www.comptia.org/blog/what-is-iaas