When Entry and Exit Behavior of Firms in an Industry

Multiple Choice

When entry and exit behavior of firms in an industry does not affect a firm's cost structure,

A) the long-run market supply curve must be horizontal.
B) the long-run market supply curve must be upward-sloping.
C) the long-run market supply curve must be downward-sloping.
D) we do not have sufficient information to determine the shape of the long-run market supply curve.