Holding Other Things Constant,diminishing Marginal Productivity Happens To

Holding other things constant,diminishing marginal productivity happens to:

A) any input, the more the input is hired.
B) labor, the more labor is hired, but not to land or capital.
C) capital inputs, the more is hired, but not to labor or land.
D) all inputs with the exception of land, the more those inputs are hired.