SAT math practice question: Functions and factors

 
Try the following SAT math question (No Calculator) that tests your understanding of x-intercepts and factors of a polynomial function.

In the $xy$-coordinate plane, the three $x$-intercepts of the graph of the polynomial function $p$ are $-1, 0,$ and $2$. Which of the following is NOT a factor of $p$?

1. $\quad x^2-1$
2. $\quad x^2+x$
3. $\quad x^2-2x$
4. $\quad x^2-x-2$