An investor has a $15000 portfolio consist
题型：单项选择题
问题：
An investor has a $15000 portfolio consisting of $10000 in stock A with an expected return of 20 percent and $ 5000 in stock B with an expected return of 10 percent. What is the investor's expected return on the portfolio（）
A.7.9%.
B.12.2%.
C.16.7%.