Step 1:
[tex]\text{Area of a circle = }\pi r^2[/tex]Step 2;
Write the given data
[tex]r=5x^3[/tex]Step 3:
Substitute in the formula to find the area of the circle.
[tex]\begin{gathered} \text{Area of the figure = }\pi(5x^3)^2 \\ =(25x^6)\pi \end{gathered}[/tex]Final answer
[tex]\begin{gathered} \text{Option C is the final answer} \\ (25x^6)\pi \end{gathered}[/tex]