Suppose that firms face the following production function: Q = 16(L^(1/2) + K^(1/2)) and firms' objective output is 96. Suppose that initially price of labor (L)=w=1 and price of capital (K)=r=1 and then price of labor (w) goes up to 2. What is the percentage of cost saving due to the ability to substitute?

a) 17.5%

b) 10%

c) 12.5%

d)15%