Answer
The answer is $\color{red}{a) 8x^3 + \dfrac{2}{x^2}}$.
Work Step by Step
Remember that a binomial consists of two monomials.
In this item, an expression with two terms but not a binomial is $8x^3 + \dfrac{2}{x^2}$, since $\dfrac{2}{x^2}$ is not considered to be a monomial. The answer is $\color{red}{a) 8x^3 + \dfrac{2}{x^2}}$.
