Suppose a Dangerous Workplace Is Made Safer Through the Installation

Suppose a dangerous workplace is made safer through the installation of guards and other equipment that reduce the physical hazards of the work environment. If we observe no reduction in injuries, we might conclude that

A) the safety equipment isn't adequate and better equipment should be installed.
B) the firm has responded by lowering wages and hiring less capable people who are more likely to be injured.
C) the injury rate before installation of the safety equipment had been underreported.
D) workers responded to the safer environment by not exercising as much care themselves, generating more injuries than if they had not changed their behavior.