Please help!

Which shows the greatest common factor of these numbers being 14?
A.
28 = 2 x 2 x 7
63 = 3 x 3 x 7
B.
28 = 2 x 2 x 7
42 = 2 x 3 x 7
C.
42 = 2 x 3 x 7
84 = 2 x 2 x 3 x 7
D.
42 = 2 x 3 x 7
63 = 3 x 3 x 7