1. We construct four portfolios by investing different weights in two stocks. The expected return and STD of these portfolios are given below.

Portfolio Expectation Return Standard Deviation

W 7.89% 10.6%

X 9.13% 10.5%

Y 8.25% 10.6%

Z 8.03% 10.5%

Assume that one of the above four portfolios is on the efficient frontier, which one is it?

1. Portfolio W is on the efficient frontier.
2. Portfolio X is on the efficient frontier.
3. Portfolio Y is on the efficient frontier.
4. Portfolio Z is on the efficient frontier.