The monomial of the 2nd degree with a coeficcient of 3 Anyone know how to do this I need help please

I assume it is the last one, 3n^2, because the degree is the exponent, which is two and the three is the coefficient, which is next to the variable, plus it is a monomial, so there is only one term, eliminating the first two, the third one is just reversed. Therefore, the answer should be the last one. Hope this helps. :)