For this case we have that by definition, a monomial is an algebraic expression that consists of a single term or in which the terms that form it are related by the product operation.
Example:
[tex]-4x * y ^ 2 * z ^ 3[/tex]
Thus, the correct option is option A.
[tex]5r ^ 2 * s ^ 3 * t ^ 4[/tex]
Answer:
Option A