Answer:
C. 2 cm
Explanation:
As the circumference is a measure of length (one dimension), we can simply divide the given circumference of circle N by the scale factor to find the circumference of circle M:
⇒ circumference of circle M = circumference of circle N ÷ scale factor
= 6 cm ÷ 3
= 2 cm
(If we were working with area, we would have to divide/multiply by the square of the scale factor, since we would be working in 2 dimensions)