D. ( + 2)
Step-by-step explanation:
A factor of an expression can either be in the form of an algebraic expression, alphabet or number. In the question, the given expression can be written as;
7 - 5 + 10 + 20
Factorizing the expression gives;
7 - 5 + 10( + 2)
Therefore, it would be observed that the factor in the expression is;
( + 2)