Rewrite the expression with grouping symbols 5m+5n

In this question , we have to rewrite the given expression by grouping and the expression is

First we have to check what is common here. And as we see that 5 is there with both terms. So the common factor is 5 here.

And on taking out 5 , we will get

And that's the required factored form.

the answer is c

hope this !