Explanation:
* Class 3 (15.4W): 802.3af
* Class 4 (30W): 802.3at
* Class 6 (60W): 802.3bt
* Class 8 (90W): 802.3bt

Explanation
802.3bz is a standard for Ethernet over twisted pair at speeds of 2.5 and 5 Gbit/s. These use the same cabling as the ubiquitous Gigabit Ethernet, yet offer higher speeds. The resulting standards are named 2.5GBASE-T and 5GBASE-T.
Option A: 2.5Gb and 5Gb Ethernet ports
This is because option A shows how to identify the speed of an Ethernet port based on its name and the standard it supports. A port that supports 2.5GBASE-T or 5GBASE-T is a multi-gigabit port that can operate at speeds of up to 2.5 Gbit/s or 5 Gbit/s over twisted pair cables23.
Therefore, option A is correct.
1: https://en.wikipedia.org/wiki/2.5GBASE-T_and_5GBASE-T 2:
https://kb.netgear.com/000049004/What-is-Multi-Gigabit-Ethernet-and-how-can-I-benefit-from-using-NETGEA
https://arstechnica.com/gadgets/2016/09/5gbps-ethernet-standard-details-8023bz/

Splitting a larger OSPF area into a number of smaller areas has several advantages for network scalability and performance. Some of these advantages are:
* It increases stability by limiting the impact of topology changes within an area. When a link or router fails in an area, only routers within that area need to run the SPF algorithm and update their routing tables. Routers in other areas are not affected by the change and do not need to recalculate their routes.
* It reduces processing overhead by reducing the size and frequency of link-state advertisements (LSAs).
LSAs are packets that contain information about the network topology and are flooded within an area.
By dividing a network into smaller areas, each area has fewer LSAs to generate, store, and process, which saves CPU and memory resources on routers.
* It reduces bandwidth consumption by reducing the amount of routing information exchanged between areas. Routers that connect different areas, called area border routers (ABRs), summarize the routing information from one area into a single LSA and advertise it to another area. This reduces the number of LSAs that need to be transmitted across area boundaries and saves network bandwidth.
References: https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/7039-1.html
https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13703-8.html