Answer:
B. r = C/2π
Step-by-step explanation:
The problem asks you to solve for r which means you have to get r by itself, or isolate the variable. You would do this by dividing both sides of the equation by 2π. The right side of the equation would cancel out, leaving you with r. The left side of the equation would simply be C/2π because C/2π cannot be simplified.
You could write your answer like this: C/2π = r
Or like this: r = C/2π
Here is my work just in case you're a visual learner: