Concept:Price fluctuation is a feature of the imperfect market, where sellers and buyers can influence prices.Explanation:The imperfect market is characterised by the ability of buyers and sellers to affect the price of commodities.Changes in demand and supply lead to frequent rises and falls in prices, which is known as price fluctuation.For example, during certain seasons, increased supply or demand can cause price changes.This pattern is not typical of a common market, supermarkets, or market failure.Answer:B. imperfect market