Which polynomial is prime?

x3 + 3x2 + 2x + 6

x3 + 3x2 - 2x - 6

10x2 - 4x + 3x + 6

10x2 - 10x + 6x - 6

A prime polynomial is a polynomial with coefficients that cannot be factored into lower degree. It is also referred as irreducible polynomial. From the choices given above, the correct answer is the third option. Because when simplified it yields 10x ² - x + 6 which cannot be reduced further.