People in the eastern part of Beirut are prevented by border guards from traveling to the western part of Beirut to shop for or sell food.This situation violates the perfect competition assumption of:

A) price-setting behavior.
B) a small number of buyers and sellers.
C) differentiated goods.
D) ease of entry and exit.

Perfect Competition

A market structure characterized by a large number of small firms, identical products, and free entry and exit, leading to price taking behavior.

Ease of Entry

Ease of entry refers to the lack of barriers for new firms to enter and compete in an industry or market, impacting competition and market dynamics.