Answer:
A; x + 1
Step-by-step explanation:
Since the viniculum in a fraction represents division, we can rewrite the expression like this:

We can already see that
could be factored:
Since anything with a "<em>one</em><em>" </em>as its base will remain one, we can rewrite:

Now, we can apply the "<em>sum of cubes</em>" formula:

Cancelling out!

Thusly, you are correct and the remainder is
.
Hope this helps! ((: