Task: Question Answering
Input (English): Question: Three pieces of timber 24 m, 28 m and 36 m long have to be divided into planks of the same length, What is the greatest possible length of each plank ?

 Option A: 7 m

 Option B: 4 m

 Option C: 42 m

 Option D: 63 m

 Option E: None of these
Output (English): Option B