None of the options. Check your question.
Did you mean (h^(7/3))(h^(14/3)), this is h^(7/3+14/3)=h^(21/3)=h⁷. None of the given answers.
As it stands the answer is (h^(7/3))(1-h^(7/3)), none of the given answers.
Or, perhaps, h⁷/3-h¹⁴/3=(h⁷/3)(1-h⁷), none of the given answers.
If you mean (h^(7/3))÷(h^(14/3)), this is h^(7/3-14/3)=h^(-7/3)=1/(h^(7/3), none of the given answers.
If you mean ((h⁷)/3)((h¹⁴)/3), this is (h²¹)/9, none of the given answers.
If you mean ((h⁷)³)(h¹⁴/3), this is h²¹(h¹⁴/3)=h³⁵/3, close to answer D.
So what did you mean?