Indian Institute of Foreign Trade 2009 Solved Paper

We have seen above that the marginal efficiency of capital depends, not only on the existing abundance or scarcity of capital-goods and the current cost of production of capital- goods, but also on current expectations as to the future yield of capital-goods - From these lines, options A, B and C can be inferred
Availability of capital is nowhere mentioned as a factor on which marginal efficiency depends
Hence, option D is the correct answer.