Which is the shortest distance mentioned in the measurements?

The shortest distance mentioned in the measurements is 1 cun. In traditional Chinese medicine and acupuncture, "cun" is a unit of measure that is often based on the individual's thumb width. It is used to determine points on the body and to understand anatomical distances relevant for treatment. A cun represents a smaller measurement and is fundamental for locating points accurately.

When comparing the distances, 1 cun is clearly less than 2 cun, 5 cun, and 8 cun, making it the shortest option. The significance of understanding measurements, especially in acupuncture, lies in the accurate localization of acupuncture points for effective treatment. Therefore, knowing that 1 cun is the smallest measurement helps practitioners apply techniques more precisely and effectively.