Let two numbers have arithmetic mean 9 and geometric mean 4. Then these numbers are the roots of the quadratic equation-

Question

( A ) $x^2 + 18x-16 =0$
( B ) $x^2 + 18x+16 =0$
( C ) $x^2 - 18x+16 =0$
( D ) $x^2 - 18x-16 =0$