Answer:
Sentences A and B contains adverb clauses.
Explanation:
Adverb clauses are those clauses that modify a verb, an adjective, or another adverb. They are also dependent clauses and usually begin with a subordinating conjunction.
Sentence A contains an adverb clause <em>"because she wanted the freshest strawberries possible"</em>. This clause describes why Aunt Carmen went to the berry farm.
Likewise, sentence B also has an adverb clause <em>"if she bakes a strawberry tart for my birthday"</em>.
On the other hand, sentence C doesn't have an adverb clause, rather it has an adjective clause-<em>"that Aunt Carmen bakes"</em>.
Thus, sentence A and B have adverb clauses.