The steps for determining the center and radius of a circle using the completing the square method are shown below: step 1 [original equation]: x2 + 4x + y2 + 2y = 20 step 2 [group like terms]: (x2 + 4x) + (y2 + 2y) = 20 step 3 [complete the quadratics]: (x2 + 4x + 4) + (y2 + 2y + 1) = 20 + (4 + 1) step 4 [simplify the equation]: (x2 + 4x + 4) + (y2 + 2y + 1) = 25 step 5 [factor each quadratic]: (x + 2)2 + (y + 1)2 = 52 step 6 [identify the center and radius]: center = (2, 1) radius = 5 which step is incorrect, and how can it be fixed? a. step 3, replace 1 with 2 b. step 5, replace 2 with 4 and replace 1 with 2 c. step 6, replace (2, 1) with (−2, −1) d. all steps are correct.