Task: Question Answering
Input (English): Problem: a circular mat with diameter 18 inches is placed on a square tabletop, each of whose sides is 24 inches long. which of the following is closest to the fraction of the tabletop covered by the mat ?
Options: ['a. 5 / 12', 'b. 3 / 5', 'c. 1 / 2', 'd. 3 / 8', 'e. 5 / 6']
Output (English): d