The ratio of the radii of two circles is 3 : 2. What is the ratio their circumference?

The correct option is A (3: 2)

Given the ratio of the radii two circle be $3:2$,
So, their radius are $3x,2x$ respectively
Circumference of circle w= $2\pi r$.
So, the circumference of the two circles be $2\pi \left(3x\right)$ and $2\pi \left(2x\right)$
The ratio their circumference is $2\pi \left(3x\right)$:$2\pi \left(2x\right)$
Hence, the ratio of circumferences would be 3 : 2.