Final answer:
Actin filaments participate in muscle cell contraction, animal cell division, and supporting microvilli, which means all the options provided (A, B, and C) are correct.
Step-by-step explanation:
Actin filaments participate in muscle cell contraction, animal cell division, and supporting microvilli. Therefore, the correct answer to the question is D. All of the choices are correct.
Actin, a protein that forms chains, is the primary component of microfilaments, which are responsible for muscle contraction. In muscle cells, these actin filaments work alongside myosin proteins to enable the cell to contract. Similarly, during animal cell division, particularly cytokinesis, actin microfilaments help form the cleavage furrow that divides the cell into two. Additionally, in the context of supporting microvilli, actin microfilaments provide strength and enable the microvilli to move independently.