What Was the Main Finding of the Institute of Medicine's

What was the main finding of the Institute of Medicine's 1999 report To Err is Human: Building a Better Healthcare System?

A) Nursing personnel need better training and education to prevent errors.
B) Registered nurses should take the lead in reducing healthcare-associated errors.
C) Faulty systems, processes, and conditions combined cause the majority of errors.
D) Over 198,000 patients die each year when they are patients in a hospital.