Need help don’t understand

Answer:
[tex] r^2 [/tex]
All choices are incorrect.
Step-by-step explanation:
Remember that [tex] r = r^1 [/tex].
Also remember the rule: [tex] \dfrac{a^m}{a^n} = a^{m - n} [/tex]
[tex] \dfrac{r^3}{r} = [/tex]
[tex] = \dfrac{r^3}{r^1} [/tex]
[tex] = r^{3 - 1} [/tex]
[tex] = r^2 [/tex]
Answer: [tex] r^2 [/tex]
All choices are incorrect.