Answer:
B.
f(x) and g(x) are closed under subtraction because when subtracted, the result will be a polynomial.
Step-by-step explanation:

Assume m>=n WOLOG


Are also a polynomial in general, but maybe in a different degree
Closure under subtraction means, for all polynomials, under the operation of subtraction, it also belongs to polynomials
1) (3-x) x (3+x)
2) 5(5-x) x (5+x)
3) (3v-wy) x (3v+wy)
4) 2(k-m) x (k+m) x (k^2+m^2)
5) (ab-4c) x (ab+4c)
Brainliest?
Is there supposed to be a picture??
i think the answer is c :)