Regulations Created Some Years Ago Allow Cell Phone Customers to Keep

Regulations created some years ago allow cell phone customers to keep the same phone number even when they switch to a different provider. This change:

A) increased the monopoly power of cell phone providers.
B) reduced the monopoly power of cell phone providers.
C) showed that lobbyists employed in the telecom industry are interested only in engaging in rent-seeking activities.
D) did not affect the degree of competition in the industry.