Which acupuncture points are indicated for caution with a full bladder?

The correct selection identifies acupuncture points that should be approached with caution in the presence of a full bladder. Ren4, K13, and ST28 are all located in regions that can influence or are close to the bladder.

Ren4, also known as "Guanyuan," is located below the navel and is associated with the reproductive and urinary systems. When the bladder is full, needling near this area could lead to discomfort or even injury.

K13 is situated close to the bladder meridian, and its stimulation when the bladder is full may lead to complications or unintentional stimulation of bladder function.

ST28, being on the Stomach meridian, is positioned near the bladder as well, and needling this point during a time when the bladder is full can also pose risks of discomfort or complications.

In contrast, other options may involve points that are either further away from the bladder or do not carry the same level of risk when the bladder is full. Therefore, the chosen response highlights the necessity of paying careful attention to bladder fullness when selecting acupuncture points related to this area and the urinary system.