An integer c is a common divisor of two integers x and y if

An integer c is a common divisor of two integers x and y if and only if c is a divisor of x and c is a divisor of y.Which of the following sets of integers could possibly be the set of all common divisors of two integers?A.{-6,-2,-1,1,2,6}B.{-6,-2,-1,0,1,2,6}C.{-6,-3,-2,-1,1,2,3,6}D.{-6,-3,-2,-1,0,1,2,3,6}E.{-6,-4,-3,-2,-1,1,2,3,4,6}看懂是问公因数问题 ,但是不知道答案为什么是C...前辈们指导下