Diminishing returns occur:

Options

A. 1.When units of a variable input are added to a fixed input and total product falls.
B. 2.When units of a variable input are added to a fixed input and marginal product falls.
C. 3.When the size of the plant is increased in the long run.
D. 4.When the quantity of the fixed input is increased and returns to the variable input falls.

Answer

b