Answer:
Sentences A and B contains adverb clauses.
Step-by-step 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 "because she wanted the freshest strawberries possible". This clause describes why Aunt Carmen went to the berry farm.
Likewise, sentence B also has an adverb clause "if she bakes a strawberry tart for my birthday".
On the other hand, sentence C doesn't have an adverb clause, rather it has an adjective clause-"that Aunt Carmen bakes".
Thus, sentence A and B have adverb clauses.