Answer:
c. firms produce identical products
Explanation:
Perfect Competition is a market form in which many buyers sell identical (homogeneous) goods to many buyers at uniform prices.
Markets are not always in equilibrium , are only when MR = MC. Sellers , being many & selling same products - have insignificant supply share & hence have no control on price determination and are only Price Takers. Similarly , many buyers also have insignificant share of market demand & hence don't have much influence over market price.