At the centre of the nipple, in the fourth intercostal space, 4 cun lateral to the midline, which point is listed?

• A. ST 16
• B. ST 17
• C. ST 18
• D. ST 15

Answer: (B)

The location described matches the point at the center of the breast: in the fourth intercostal space, 4 cun lateral to the midline. That point is ST17. The nipple region sits at that level, so ST17 is the chest point defined as the center of the breast. The other points in that area occupy different intercostal spaces or different lateral offsets, so they do not align with the nipple center. This is why the described location best identifies ST17.