Final answer:
Capping proteins b) stabilize microfilaments by binding to their ends, preventing excessive growth or shrinkage. This helps maintain cell structure and allows motor proteins to slide along the microfilaments for cell motility. Hence, b) is correct.
Step-by-step explanation:
Capping proteins stabilize microfilaments, not intermediate filaments or microtubules. They bind to the ends of microfilaments, adding thickness and preventing the filaments from growing or shrinking too much.
This helps maintain the overall structure and function of the cell. Capping proteins also play a role in cell motility by allowing motor proteins to slide along microfilaments.