Use the formula a2 – b2 = (a + b)(a – b) to factor completely. What are the factors of 36x8 – 49?A. (9x4 – 1)(4x2 + 49)B. (36x4 – 7)(x2 + 7)C. (6x4 – 7)(6x4 + 7D. (6x8 – 7)(6x + 7)