Answer:
Option D.
Explanation:
The given polynomials are
and

Now we will subtract the 1st polynomial from second.
- (
)
=

=

Now the degree of both the terms of the polynomial is
Degree of 1st term = 2 + 2 = 4
Degree of 2nd term = 1 + 5 = 6
Therefore, the highest degree of the polynomial is 6.
Option D. will be the answer.