Implementing and Administering Cisco Solutions (200-301 CCNA) v1.1

Physical Access Control refers to the measures and systems put in place to restrict entry to physical spaces, such as buildings, rooms, or areas within a facility. It aims to ensure that only authorized individuals are granted access to specific locations based on their roles, permissions, or clearances.

By using the ID badge of only one person to gain entry, the group of employees circumvents the intended physical access control measures. Each employee should have their own ID badge, and their access permissions should be associated with their individual credentials.

This question is Cisco use their word games on the question to confuse people. The question is in plain terms ask what need to be change to make the router neighbors. Below is a section from the CCNA Offical Cert guide 200-301. "Mismatched OSPF Network Types Earlier in this chapter you read about the OSPF broadcast network type, which uses a DR/BDR, and the OSPF point-to-point network type, which does not.
Interestingly, if you misconfigure network type settings such that one router uses broadcast, and the other uses point-to-point, the following occurs:

1. The two routers become fully adjacent neighbors (that is, they reach a full state).
2. They exchange their LSDBs.
3. They do not add IP routes to the IP routing table."

Have matching Hello timer is one of the requirements for OSPF to neighbors to become FULL.

Authentication, authorization, and accounting (AAA) is a term for a framework for intelligently controlling access to computer resources, enforcing policies, auditing usage, and providing the information necessary to bill for services. These combined processes are considered important for effective network management and security.

As the first process, authentication provides a way of identifying a user, typically by having the user enter a valid user name and valid password before access is granted. The process of authentication is based on each user having a unique set of criteria for gaining access. The AAA server compares a user's authentication credentials with other user credentials stored in a database. If the credentials match, the user is granted access to the network. If the credentials are at variance, authentication fails and network access is denied.

When connecting two like devices together (e.g., two computers or two switches) directly without an intermediate device like a hub or a switch, and auto detection MDI-X (Media Dependent Interface with Crossover) is unavailable, a crossover cable is used. In a crossover cable, the transmit (TX) pins on one end are connected to the receive (RX) pins on the other end, and vice versa.

References:
https://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r4-0/addr_serv/configuration/guide/
ic40crs1book_chapter10.html

The administrative distance for the destination route is 1 because the gateway of last resort is configured with an administrative distance of 1 (indicated by the [1/0] in the routing table output) and the destination route for the Internet (0.0.0.0/0) is learned via that gateway.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/25ew/configuration/guide/conf/
port_sec.html

The lowest Administrative Distance will be used to select the route. In this cast, the route using 172.16.20.2 is using the default value for a static route, which is 1. The other default route has a configured
AD of 20.