To solve this question, the user needs to know the definitions of the given options and the context of the sentence.

The sentence states that Coach Calhoun tried to motivate or encourage his team to try harder when facing overwhelming odds.

Now, let's go through each option and explain why it is right or wrong:

A. flout: This word means to openly disregard or disobey a law, rule, or convention. It is not the correct word for the given sentence.

B. instigate: This word means to bring about or initiate an action or event. It is not the correct word for the given sentence.

C. emulate: This word means to imitate or match the actions or qualities of someone or something else. It is not the correct word for the given sentence.

D. exhort: This word means to strongly encourage or urge someone to do something. This is the correct word for the given sentence as it accurately describes Coach Calhoun's actions of motivating his team to try harder.

Therefore, the answer is: D. exhort