The greatest common factor of a polynomial is the largest expression that divides all of the terms of the polynomial. In this case, we have:
First, find the GCF of the coefficients of the terms. The coefficients are 2, 14 and 6, their GCF is 2.
On the other hand, notice that the factor (c+y) is a common factor for all three terms. Find the greatest power of (c+y) that divides all the terms. Since the lowest power of (c+y) in the expression is 2, then, the greatest power of (c+y) that divides all the terms is (c+y)^2.
The GCF of the expression is the product of the GCF of the coefficients and the GCF of the factors with variables.
Then, the GCF of the expression is:
Factor out 2(c+y)^2 from the expression:
Therefore, the answer is option A and the expression inside the box should be: