Suppose that firms face the following production function: Q = L^(1/2) K^(1/2) and firm has K units of fixed capital in short run. Suppose also that price of labor (w) is 4 and price of capital (r) is 1 and firm's objective output is 144. At what level of K short run total cost would be equal to the long run total cost?

a) 36

b) 72

c) 288

d) 144