Answer:
D. The economy or the weather can make a small town fall apart.
Step-by-step explanation:
A compound subject is a subject consisting of two or more nouns. When a sentence has a compound subject, the nouns are often joined by a comma or by coordinating conjunction like or, nor, and or neither. In sentence D, "The economy or the weather" is a compound subject because both nouns act as subjects (They perfom the main action), and they are joined by "or."