The correct answer is: B. 9.50%
The HML portfolio is a hedge fund strategy that seeks to profit from the tendency of high-book-to-market stocks to outperform low-book-to-market stocks over time. The HML portfolio is calculated by taking the difference between the returns of a high-book-to-market portfolio and a low-book-to-market portfolio.
In this case, the high-book-to-market portfolio has a return of 6.5% and the low-book-to-market portfolio has a return of 3.0%. Therefore, the HML portfolio return is 9.50%.
Option A is incorrect because it is the return of the low-book-to-market portfolio. Option C is incorrect because it is the return of the high-book-to-market portfolio. Option D is incorrect because it is the ratio of the returns of the high-book-to-market portfolio and the low-book-to-market portfolio.