#### Answer

This expression is a monomial since there is only one single term in the polynomial. Its degree is 3.

#### Work Step by Step

A polynomial is classified as a monomial, binomial, trinomial, etc. based on the number of terms in it. The given polynomial $\frac{4}{3}\pi r^{3}$ contains only one term. Hence it is classified as a monomial.
The greatest degree of the terms in a polynomial is called the degree of the polynomial. In this case, it is 3.