If your portfolio consists of the 6 stocks with the following returns {2.2%, -5.4%, 15.6%, 8.9%, 21.3%, -1.3%} and the following weights {20%, 20%, 15%, 15%, 5%, 25%}, what is the expected return on your portfolio?

a. 4.78

b. not enough information

c. 3.78

d. 2.91