Jeff learned that the product of the polynomials (a + b)(a2 – ab + b2) was a special pattern that would result in a sum of cubes, a3 + b3. His teacher put four products on the board and asked the class to identify which product would result in a sum of cubes if a = 2x and b = y. Which product should Jeff choose?

a
(2x + y)(4x2 + 2xy – y2)

b
(2x + y)(4x2 – 2xy + y2)

c
(2x + y)(2x2 + 2xy – y2)

d
(2x + y)(2x2 – 2xy + y2)