Answer:
The answer is indeed b. adjective clause
Step-by-step explanation:
A dependent adjective clause is a group of words containing a subject and a verb. It offers further description or information - similar to what an adjective does - about something that was mentioned in another sentence. Adjective clauses are often introduced by relative pronouns such as who, which, or that.
In the sentence we are analyzing here, the clause "who bought me a puppy for my birthday" offers further information about "the one" - and "the one" refers to "my uncle".