The Key Assumption of the Income-Leisure Model

The key assumption of the income-leisure model:

A) is not applicable to the real world and so negates the usefulness of the model.
B) is not valid as employers will not cater to workers' income-leisure choices.
C) holds good in general because workers can vary work hours with overtime,leaves without pay and early retirement.
D) is only applicable to entrepreneurs and not salaried workers who are associated with less promising financial rewards.