Determine Whether the Expression Is a Polynomial $- 20 y z + 6 z ^ { 2 }$

Multiple Choice

Determine whether the expression is a polynomial. If the expression is a polynomial, state whether it is a monomial,
binomial, or trinomial. If the expression is not a polynomial, indicate why not.
- $- 20 y z + 6 z ^ { 2 }$

A) not polynomial, first term contains 2 different variables y and z
B) monomial
C) trinomial
D) binomial