The production function is F(L, K) = L^(1/2) K^(1/2). In the short-run, the firm sells its output at a price of $10 per unit, and can hire labor at a wage of $5 per unit. Capital is fixed at 25 units. The amount of labor that minimizes costs is:
a. L=1
b. L=2
c. L-10
d. None is correct