Answer:
b. compound
Step-by-step explanation:
A compound sentence is a sentence containing two or more independent clauses with related ideas, and that may be joined by a semicolon or a coordinating conjunction like and, but, so, for, nor, or, yet.
The sentence provided is a compound sentence because it consists of two independent clauses: “I want to buy those shoes” and “I don’t have enough money” (They are independent because they express complete thoughts on their own) that are joined by the coordinating conjunction “but.”