Assessing Risk-Adjusted Performance Using Sharpe Ratio

A wealthy investor, Sarah, manages a $1 million portfolio and wishes to evaluate its performance over the past year. The portfolio achieved a return of 12%, while the benchmark index returned 8%. Sarah also notes that the standard deviation of her portfolio’s returns was 10%, while the benchmark's standard deviation was 5%.

Sarah is particularly interested in assessing how effectively she is taking on risk relative to the benchmark. She considers using the Sharpe ratio as a measure of risk-adjusted return. Based on this information, which statement about the Sharpe ratio for Sarah's portfolio compared to the benchmark is most accurate?