Why Are the Muscles Used for Movement in Insects Often

Why are the muscles used for movement in insects often pennate?

A) The limited space within insect exoskeletons requires muscle that generates high force without changing size significantly.
B) The internal muscle includes both flexor and extensor muscles.
C) Insects require muscle that generates large length changes to compensate for lack of joints in the skeleton.
D) Insects moult to grow their skeleton.