Answer:
b. Compound
Step-by-step explanation:
A compound sentence is a sentence containing two or more independent clauses with related ideas joined by a semicolon, a comma, or coordinating conjunction such as and, but, so, for, nor, or and yet.
The sentence provided is a compound sentence because it consists of two independent clauses joined by the coordinating conjunction “but.” Besides, we can tell that these clauses are independent because they both express a complete idea on their own.