ACE Company acquired $500,000 to construct a new warehouse. To obtain this fund, the company issued 3,000 preferred stocks with $100 par value and 8% dividend rate for $300,000 and bonds for $100,000 with 5% interest, and borrowed the rest from its bank with 6% interest rate. The company requires a 3% buffer margin.

What is the required rate of return on this project?

10%

13.9%

12%

10.9%

7%