Final answer:
The sentence that correctly punctuates the adverb clause 'if my mom calls' is option B: If my mom calls, tell her that I will call her back later.
Step-by-step explanation:
The sentence that correctly punctuates the adverb clause 'if my mom calls' is option B: If my mom calls, tell her that I will call her back later.
When an adverb clause begins a sentence, it should be followed by a comma. In this case, 'If my mom calls' is the adverb clause, and the comma after it in option B correctly punctuates the sentence.
Using the correct punctuation ensures that sentences are clear and properly convey the intended meaning.
Learn more about Punctuation in English sentences