The correct option is (B): \(11(\frac{1}{4})\)
Explanation: To find out how many baskets the worker makes, we first convert the time taken to make one basket into hours and the total working time into a single fraction.
1. Time taken to make one basket = \( \frac{2}{3} \) hours.
2. Total working time = \( 7 \frac{1}{2} = 7.5 = \frac{15}{2} \) hours.
Next, we calculate how many baskets he can make in that time:
\[\text{Number of baskets} = \frac{\text{Total time worked}}{\text{Time per basket}} = \frac{\frac{15}{2}}{\frac{2}{3}} = \frac{15}{2} \times \frac{3}{2} =\frac{45}{4} = 11 \frac{1}{4}\]
So, the worker will make \( 11 \frac{1}{4} \) baskets. Thus, the answer is \( B: 11 \frac{1}{4} \).