Answer:
Option B
![2\pi\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/txw13ftgzba2ubv82gon51g33utj3diivz.png)
Explanation:
step 1
Find the circumference of the circle
The circumference is equal to
![C=2\pi r](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kmguleyi3d7rsbh4zj0jg7p7fumid62phf.png)
we have
![r=6\ units](https://img.qammunity.org/2020/formulas/mathematics/middle-school/u7l42qqhnkb7vihyqo64fz2sjzb8f5mqub.png)
substitute
![C=2\pi (6)](https://img.qammunity.org/2020/formulas/mathematics/high-school/o3lbdsiyoyiqfhzv9q1cch4yiigvvkccgl.png)
![C=12\pi\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/ezgjblc5xlrfpbj4l6asxqksg3ezpcn1o8.png)
step 2
Find the length of an arc measuring 60°
we know that
The circumference of the circle subtends a central angle of 360 degrees
so
using proportion
find the length of an arc measuring 60°
![(12\pi)/(360)=(x)/(60)\\ \\x=12\pi(60)/360\\\\x=2\pi\ units](https://img.qammunity.org/2020/formulas/mathematics/high-school/qseqeu3erl8esta1sa4jop9l9jm3c2on6o.png)