Answer:
B. more soldies who had lost a limb returned home
The key evolutionary development of animals seen for the first time in sponges is that of Multicellularity. A Multicellular organism has a longer lifespan than an unicellular organism and since it has multiple cells, it can perform more functions. Sponges do not have distinct circulatory, respiratory, digestive, and excretory systems – instead the water flow system supports all these functions.
The sliding filament theory of muscle contraction was developed to fit the differences observed in the named bands on the sarcomere at different degrees of muscle contraction and relaxation. The mechanism of contraction is the binding of myosin to actin, forming cross-bridges that generate filament movement.