A monomial is polynomial containing one term. Consider the options:
Option A: y/x
The polynomial cannot involve division by a variable. So this is not a polynomial and therefore not a monomial.
Option B: Contains only 1 term. So it is a polynomial
Option C: Contains more than 1 term. So not a monomial
Option D: Contains a negative exponent. So not a polynomial and therefore not monomial.
So the correct answer is option B
