You invested $11,000 in a portfolio with an expected return of 3.8 per cent and $19,000 in a portfolio with an expected return of 13.7 per cent. The expected return of the combined portfolio is (as a percentage to two decimal places eg 2.881% is 2.88))

a.10.07%

b. 11.08%

c. 4.30%

d. 6.42%