Which of the following is an assumption underlying the political model of decision making?

a$.$ It assumes that decision makers operate to accomplish goals that are known and agreed on$.$

b$.$ It assumes that decisions are the result of bargaining and discussion among coalition members.

c$.$ It assumes that managers have the time, resources, and mental capacity to identify all dimensions of the problem at hand.

d$.$ It assumes that decision makers are completely rational and use logic to assign values, order preferences, and evaluate alternatives.