What Is the Main Difference Between Fred Fiedler's Contingency Theory

What is the main difference between Fred Fiedler's contingency theory of leadership and Hersey and Blanchard's Situational Leader model?

A) The contingency theory assumes that the leader's style doesn't change,while the Situational Leader model assumes that a leader can adapt his or her style to the situation.
B) The contingency theory assumes that style is flexible,while the Situational Leader model assumes that style is fixed and unchangeable.
C) The contingency theory has been disproven by research studies,while the Situational Leader model has been empirically proven.
D) The contingency theory was popular before meta-analysis allowed analysis of multiple studies,while the Situational Leader model makes use of multiple avenues of study.
E) The contingency theory does not allow for external influences on the leaders,while the Situational Leader model takes into account the things that influence leaders from outside their organizations.