The expression (x + y +z)²⁰⁰⁶ + (x - y - z)²⁰⁰⁶ is simplified by expanding it and combining like terms. How many terms are in the simplified expression?
(A) 6018
(B) 671, 676
(C) 1, 007, 514
(D) 1, 008, 016
(E) 2, 015, 028