Task: Question Answering
Input (English): Question: A farm used two harvesting machines, H and K, to harvest 100 acres of wheat. Harvesting machine H, working alone at its constant rate, harvested 40 acres of wheat in 8 hours. Then harvesting machine K was brought in, and harvesting machines H and K, working together at their respective constant rates, harvested the remaining acres of wheat in 3 hours. Harvesting machine K harvested how many acres of wheat per hour?

 Option A:  7

 Option B:  8

 Option C:  12

 Option D:  13

 Option E:  17
Output (English): Option E