Answer
$\color{red}{\text{This expression is NOT a polynomial}}$.
Work Step by Step
Remember that a term is considered as a monomial ONLY IF it is a PRODUCT of constants and/or variables.
In this item, the terms are $x^2$, $x$, $1$, $x^3$ and $-7$; however, when combined, they produce a QUOTIENT of constants and/or variables. Therefore, $\color{red}{\text{this expression is NOT a polynomial}}$.