Which of the following is a monomial? 12c c2 − 16 c2 + c + 6 c3 + 4c2 − 12c + 7

In mathematics, the term "monomial" is used to refer to an algebraic expression that contains only one term.
Monomials can either be:
1- numbers (example: 2, 27,...etc)
2- numbers and variables multiplied together (example: 7xy , 33x,etc)
3- variables multiplied together (example: xy, abc, etc)

Based on the above explanation, we will find that the choice that fits the definition of monomial is:
the first choice: 12c