The Input Contract Curve Represents

The input contract curve represents:

A) All consumption good allocations in an Edgeworth box that are exchange efficient.
B) all input allocations in an Edgeworth box for inputs that are input efficient.
C) All possible combinations of consumption goods that can be produced in an economy given the economy's available supply of inputs.
D) the different combinations of capital and labor inputs that will produce a given level of output for a particular good.