Rational choice theory assumes that if action a$1$ is preferred to action a$2$ and action a$2$ is preferred to action a$3,$ then action a$1$ should be preferred to action a$3.$ This is known as $\_\_\_\_\_.$

a$.$

Completeness.

b$.$

Transitivity.

c$.$

Independence of irrelevant alternatives.

d$.$

Law of multiple criteria