An Unregulated Industry Has a Lerner Index of Zero

Multiple Choice

An unregulated industry has a Lerner index of zero.These numbers:

A) reveal that social welfare would be improved by regulating the firms.
B) are consistent with the industry being monopolistically competitive.
C) are consistent with the industry being perfectly competitive.
D) reveal that social welfare would be improved by regulating the firms and are consistent with the industry being monopolistically competitive.