Answer:
x^2 +16 is prime
Explanation:
A prime polynomial is one that cannot be factored using integers.
- x^2 -36 = (x -6)(x +6) . . . . not prime
- x^2 +16 . . . . . prime
- x^2 -7x +12 = (x -3)(x -4) . . . . not prime
- x^2 -x -20 = (x -5)(x +4) . . . . not prime