Which of these options is a compound sentence?

Choose 1

(Choice A)
A
Gizmo is scared of thunder: he hides under the covers whenever it storms.

(Choice B)
B
Whenever it storms, Gizmo hides under the covers.

(Choice C)
C
Gizmo hides under the covers when it storms due to his fear of thunder.

Choice B

Explanation:

A compound sentence is a sentence that has at least two independent clauses joined by a comma, semicolon or conjunction. ... An example of a compound sentence is, 'This house is too expensive, and that house is too small. A compound sentence joins two or more sentences that have related ideas of equal importance. The two sentences go together. Each sentence or independent clause must still have a subject and a verb. Use a comma to separate independent clauses in a compound sentence when they are separated by a conjunction. The comma goes after the first clause and before the coordinating conjunction that separates the clauses. Make sure they are independent clauses and not some other construction where commas are not required.

answer; i believe the correct answer is ( indirect characterization);