Match the items given in List-I with those given in the List-II and suggest the correct option.

List-I	List-II
a. Marginal productivity/Average productivity	1. Isoquant curve
b. Substitutability of inputs	2. Isocost line
c. Constant negative slope	3. Production Function
d. Convex to origin	4. Elasticity of production

A. a-1, b-2, c-3, d-4

B. a-2, b-1, c-4, d-3

C. a-4, b-3, c-2, d-1

D. a-3, b-4, c-1, d-2

Answer: Option C