Why can the following problem NOT be factored?

x2−7x+9
(1 point)
Responses

The coefficients are all odd integers.
The coefficients are all odd integers.

There is not a greatest common factor.
There is not a greatest common factor.

There are no two integers that give a product of 9 and a sum of -7.
There are no two integers that give a product of 9 and a sum of -7.

Sorry, but this problem can be factored!

The problem cannot be factored because there are no two integers that give a product of 9 and a sum of -7.