8 men, working 9 hours a day can complete a work in 24 days. How many hours a day must 12 men work to complete the same work in 16 days?
Choose the most appropriate option:
A) 6 B) 7 C) 8 D) 9 E) 10

Rationale: "the number of hours required to complete the work is 8 * 9 * 24 = 1728 12 × 16 × ( x ) = 1728 x = 9 the answer is d ."
Answer: D