Answer: Option (A) is correct.
Step-by-step explanation:
Each of the buyer and seller are small when we are relating it with the whole market. so, there will be no power in the hands of a single decision maker and if a firm wants to change their prices then it will not have any influence on the market price. In a competitive market, there are large number of buyers and sellers, thus, one buyer or seller doesn't have any impact on the market price.