Answer:
The correct answer is TIENE.
Explanation:
"Mi hermano tiene 15 años" can be literally translated to "my brother has 15 years old". "Mi hermano" is the subject, while "15" is the adjective modifying the noun "años".
"Tener" is a verb that specifically conveys the possession of something, whether it's an object or something more abstract like age. The correct conjugation of this verb for a singular masculine person (mi hermano) is "tiene". Therefore, the only possible way to complete the sentence is with TIENE.
