The market structure of perfect competition exists when there are a small number of interdependent firms that constitute the entire market. there are many producers of a homogeneous product. there are many producers of differentiated products. there is a single producer of a product.

Acompany enters into a short futures contract to sell 5,000 bushels of wheat for 250 cents per bushel. the initial margin is $3,000 and the maintenance margin is $2,000. what price change would lead to a margin call? under what circumstances could $1,500 be withdrawn from the margin account?