To determine the percentage of farmers with sandy soil who prefer producing carrots, we use the formula for relative frequency:
\[ \text{Relative Frequency} = \frac{\text{Number of farmers who prefer carrots}}{\text{Total number of farmers with sandy soil}} \times 100 \]
In this case, the number of farmers with sandy soil who prefer carrots is 120, and the total number of farmers with sandy soil is 170.
Plugging in the numbers:
\[ \text{Relative Frequency} = \frac{120}{170} \times 100 \]
Calculating this:
\[ \frac{120}{170} \approx 0.7059 \]
Now, converting this to a percentage:
\[ 0.7059 \times 100 \approx 70.6% \]
Therefore, the percentage of farmers with sandy soil who prefer producing carrots is 70.6%.
The correct response is:
70.6%