In C, denominator is x-3 and denominator should not be 0 . So we set x-3 to 0 and solve for x, that is
x-3=0
x=3
So domain can't be 3.
And if we see the equation, we will get the numerator and denominator both have same degree. So
Horizontal asymptote= numerator's leading coefficient /denominator's leading coefficient .
y= 2/1 =2
So at y=2, there is a horizontal asymptote , because of which y =2 is not a part of the range .
THerefore the correct option is C .