Answer:
![\large\boxe{D)\ (1)/(2)\pi\ feet}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8z1jt1g2kipxbiiv2x8afmhhsyfcmyn0f6.png)
Explanation:
Step 1:
Calculate the circumference of both circles.
The formula of a circumference:of a circle with radius r:
![C=2\pi r](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kmguleyi3d7rsbh4zj0jg7p7fumid62phf.png)
The circle R:
![C_R=2\pi\left((2)/(3)\right)=(4\pi)/(3)\ ft](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hd9kqzp5j9u4x7uzip319uzdr1u0p8ztgc.png)
The circle S:
![C_S=2\pi\left((3)/(4)\right)=(3\pi)/(2)\ ft](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sipuyzj1x9bgf01b0cae0syhs8f6pr1z4n.png)
The length of the intercepted arc for circle R is
![l=(4\pi)/(9)\ ft](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ojk1f7govt01qan7me011h45am9qhtxz77.png)
Step 2:
Calculate what the part of the circumference of the circle R is the intercepted arc:
![(4\pi)/(9):(4\pi)/(3)=(4\pi)/(9)\cdot(3)/(4\pi)=(1)/(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/j21m3kfflbv6j3dgcuasqfm3xkczn4ic8c.png)
The same length of the circumference of the circle S is searched for the length of the intercepted arc for circle S.
Step 3:
Calculate the length of the intercepted arc for circle S:
![(1)/(3)\cdot(3\pi)/(2)=(1)/(2)\pi\ ft](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pdg39fg9o0t5ln8dr9jk4syw8f47v32eop.png)