the complete question in the attached figure
we have that
(x² - 25)/ (x - 5)
we know
(x² - 25)-------------> (Difference of two squares)----------> (x+5)*(x-5)
then
(x² - 25)/ (x - 5)-------> (x+5)*(x-5)/(x-5)------------> (x+5)
the answer is the option B)
(x+5)