Full answers! need all the i can get

A
This is one of those questions that is hard to explain, because I don't know what you know. I'll start with the most obvious reason I know. At x = -1 the top and bottom of the function is 0/0. zero/zero can give indeterminate results and you must look for other ways of explaining what is going on. Here's another thought which is less reliable.

The fraction factors.
(x + 1)*(x - 1)

    (x + 1)
The two common factors cancel and you are left with f(x) = x - 1

If you have a graphing calculation you can put this in as y = x - 1 and you see that it is a straight line.

Question B is much nicer
when you put x = 1 into the fraction, you get 0 /2 which gives you 0. That's much easier to handle because the answer is 0.
you are still graphing y = x - 1, but this time the graph is much more well behaved.

The answer to your question is the last one