When Company Ownership Is Diffuse

When company ownership is diffuse,

A) a "free rider" problem discourages shareholder activism.
B) the large number of shareholders ensures strong monitoring of managerial behavior because with a large enough group, there's almost always someone who will to incur the costs of monitoring management.
C) few shareholders have a strong enough incentive to incur the costs of monitoring management.
D) both a and c are correct