From Rosenthal and Rosnow's (1975) Research on the Factors That

From Rosenthal and Rosnow's (1975) research on the factors that affect the decision to volunteer for research, we can conclude that:

A) situational variables are more important than subject variables.
B) subject variables are more important than situational variables.
C) situational and subject variables have no influence on the decision to participate.
D) both subject and situational variables affect a potential participant's decision to participate.