a)none
B)7
C)6i
D)I-6
E) - square of 7
( look at the picture better)

The correct answer is A). None
Step-by-step explanation:
The given quadratic polynomial has 3 roots and some of roots are x=[tex]\sqrt{7}[/tex] and x=6+i
It is necessary to note that one of the roots is a complex number and root of complex number always in pair of the conjugate to each other.
Since x=6+i
Conjugate of (6+i) is (6-i)
Therefore, (6-i) is 3rd required root of a polynomial
The correct answer is A). None