Large Trials Targeting Psychosocial Variables to Reduce Morbidity and Mortality

Large trials targeting psychosocial variables to reduce morbidity and mortality following cardiovascular disease have:

A) been universally supportive.
B) not been conducted.
C) not been universally supportive.
D) been impossible to undertake due to the large number of factors that would need to be accounted for.
E) been in the progress with results unknown at this time.