You have a total of $100,000 to invest in a portfolio of assets. The portfolio is composed of a risky asset with an expected rate of return of 15% and a standard deviation of 21% and a Treasury bill with a rate of return of 5%. How much money should be invested in the risky asset to form a portfolio with an expected return of 11%?

a) 60,000

b) 40,000

c) 70,000

d) 30,000