Do the following functions exhibit increasing, constant, or decreasing returns to scale? What happens to the marginal product of each individual factor as that factor is increased and the other factor held constant?

a. q= 3L+2K

b. q= (2L + 2K)^.5

C. q=3LK^2

d. q=L^.5K^.5

e. q=4L^.5 + 4K