Aprime polynomial is an irreducible polynomial with integer coefficients that cannot be factored into polynomials of lower degree over the real number system. which trinomial is prime?

a.) x2 – 7x – 18
b.) x2 – 9x – 18
c.)x2 + 3x – 18
d.)x2 + 17x – 18

I believe the correct answer is B. It is the polynomial x^2 – 9x – 18 that is a prime polynomial. Other options can be factored out to a number under the real number system while option B cannot give a whole number. The factors are as follows:

A.) x2 – 7x – 18           9 and -2
B.) x2 – 9x – 18           10.68465844 and -1.684658438
C.)x2 + 3x – 18            3 and -6
D.)x2 + 17x – 18         1 and -18