Which choice best describes the underlined words in the sentence?

I disagree with your answer.

Ummmm, C?

Since the whole sentence is underlined, then the answer can't be A, B, or C.

Ohh, then what would it be called? Just a regular sentence, like no specific name?

Right. It's a complete sentence.

Look at the stars and planets on a clear night.

To determine the correct choice, let's break down the sentence. The sentence is, "Use a star chart to identify the stars and planets on a clear night." In this sentence, the underlined words are "Use a star chart to identify the stars and planets on a clear night." We need to determine which choice best describes these underlined words.

A simple predicate is the main verb or verb phrase in a sentence that expresses the action or state of being. In this sentence, the simple predicate is "Use."

A compound predicate is when there are multiple verbs or verb phrases connected by a coordinating conjunction. However, in this sentence, there is only one verb phrase, "to identify the stars and planets on a clear night," so it cannot be a compound predicate.

A complete predicate includes the main verb and all accompanying words and phrases, expressing the action or state of being. The complete predicate in this sentence is "use a star chart to identify the stars and planets on a clear night."

Based on the explanations above, the best choice to describe the underlined words in the sentence is C - complete predicate.