Simply the expression completely

(12x^2 + 12x + 5) + (-x^2 - 1) =

13x^2 +12x + 6
13x^4 + 12x^2 + 6
11x^4 +12x^2 + 4
23x^6 + 4
23x^3 + 4
11x^2 + 12x + 4