A)declines as the Firm Substitutes Labor for Capital

Multiple Choice

$$\text { For the production function } \mathrm { Q } = \mathrm { aL } + \mathrm { bK } \text {, where } \mathrm { a } \text { and } \mathrm { b } \text { are constants, the } M R T S _ { L , K }$$

A) declines as the firm substitutes labor for capital.
B) remains constant as the firm substitutes labor for capital.
C) implies upward-sloping, straight-line isoquants.
D) is undefined.