They have a form of communication just between dogs
Answer: Many buses in the terminal are waiting to depart.
This sentence is the only one that uses a verb that agrees with its subject. In this case, the subject is "buses." The verb, which is "are," agrees with the subject because it also takes a plural form. All of the other options have verbs that do not agree with the subjects of the sentences.
If you are talking about Theodore Roosevelt then what helped him was the
fact that he was from a wealthy family that didn't send him to school
but rather had him tutored at home and more or less groomed him for the
role of a diplomat. He used what he was taught by tutors to get degrees
from Harvard and Columbia which is not a small feat.
Someone would use the ethos appeal to enhance their credibility about a certain topic.