The point R has coordinates (-5,-5) and the image point R' has coordinates (2,-7).
If
- -5+a=2, then a=2-(-5)=2+5=7;
- -5+b=-7, then b=-7-(-5)=-7+5=-2.
Thus, the translation rule is
(x,y)→(x+7,y-2)
or

If point U has coordinates (-5,1), then its image U' has coordinates (-5+7,1-2) that is (2,-1).
Answer: correct choice is B