The maximum number of students among them 640 pens and 520 pencils can be distributed in such a way that each student get the same number of pens and same number of pencils?  Choose the correct option
A) 40  B) 45  C) 50  D) 55  E) 60

Rationale: "number of pens = 640 number of pencils = 520 required number of students = h . c . f . of 640 and 520 = 40 answer is a"
Answer: A