Task: Question Answering
Input (English): Problem: a can finish a work in 72 days, b in 9 days and c in 2 days, b and c start the work but are forced to leave after 3 days. the remaining work was done by a in ?
Options: a. 30 days, b. 12 days, c. 6 days, d. 7 days, e. 8 days
Output (English): a