A competitive, profit-maximizing firm uses two inputs L and K. Its production function is F(L,K) = L^{1/2} K^{1/2}. Its output sells for $5 per unit. The price of input L is $1 per unit. If the price of output rises to $6 per unit but factor prices do not change,
a. it will increase its purchases of factor L by 3/4 units.
b. None of the others.
c. we need to know the price of factor b to be able to determine the change in demand for L
d. it will increase its purchases of factor L by 11/4 units.
e. it will increase its purchases of factor L by 9/4 units.