The answer is B. When dividing exponents, you divide the coefficients and subtract the exponents from the numerator to the denominator.
So, in this case, 16/8 is 2 (eliminating C and D). Then, you subtract the exponents on r and s. For r, that’s 6-2 so the answer will be r^4. For s, that’s 3-6 so the answer will be s^-3, or 1/s^3. Put it all together and you get 2r^4/s^3, or B.
