Task: Question Answering
Input (English): Question: Three printing presses, P, S, and T, working together at their respective constant rates, can do a certain printing job in 4 hours. S and T, working together at their respective constant rates, can do the same job in 5 hours. How many hours would it take P, working alone at its constant rate, to do the same job?

 Option A: 8

 Option B: 10

 Option C: 12

 Option D: 15

 Option E: 20
Output (English): Option E