After a recent security breach and a RADIUS failure, an engineer must secure the console port of each enterprise router with a local username and password. Which configuration must the engineer apply to accomplish this task?

A. aaa new-model
line con 0
password plaintextpassword
privilege level 15
B. aaa new-model
aaa authorization exec default local
aaa authentication login default radius
username localuser privilege 15 secret plaintextpassword
C. username localuser secret plaintextpassword
line con 0
no login local
privilege level 15
D. username localuser secret plaintextpassword
line con 0
login authentication default
privilege level 15