The answer is option B "." Rational exponents are exponents that are integers and are fractions. Remember that rational numbers are numbers that can be changed into a fraction but it's the same way with rational exponents they are integers (negative or positive) that can be rewritten as fractions.
The rational exponent expression of sixth root of f is <span>f to the one sixth power proof A^1/n, is called n-th root of A, for all n differ from zero</span>
