In Imperfectly Competitive Markets, "Administered" Prices Usually Change Than Prices

In imperfectly competitive markets, "administered" prices usually change than prices in perfectly competitive markets, because _ .

A) more often; perfectly competitive firms are price takers
B) less often; changing prices is costless
C) less often; changing prices is costly
D) more often; price becomes a strategic choice
E) more often; they are more flexible