Human beings are complex, and few, if any, simple and universal principles explain organizational behavior. Nevertheless, it does not mean that OB cannot offer reasonably accurate explanations of human behavior or make valid predictions. It does mean that OB concepts must $\_\_\_\_\_\_\_\_.$

a$.$

attempt to establish cause$-$and$-$effect relationships

b$.$

focus on the reliability and validity of research data

c$.$

be consistently applicable across a wide range of situations

d$.$

avoid assumptions

e$.$

reflect situational, or contingency, conditions