I have tried hard to get good photographs of my friends. Which word is the adverb? A. Friends B. Hard C. Tried D. Good

Well, if we know that an adverb is a modifier of verb's or word groups such as a circumstance, a time, or a place then looking at this question would be more understandable.

In this case, examine your options.

A) is a noun. - - > noun is a person place or thing-->e. g friends.

B) is unfitting to the question being asked I should think.

C) is something like what we are looking for. It is a verb, it is an action. An adverb modifies an action.

Does this make sense?

Adverbs describe the verb. The verb is the action of the sentence. In this sentence, I believe "Hard" would be the adverb.