Huànmén (M-BW-6) is located how far lateral to the spinous process of which vertebra?

• A. 1.5 cun lateral to the lower border of the spinous process of the fifth thoracic vertebra (T5).
• B. 0.5 to 1 cun lateral to the depression below the spinous process of DU-14.
• C. 3 cun lateral to the midline on the lower abdomen, level with Ren-3.
• D. Center of the frenulum of the tongue between Jīnjīn and Yùyè.

Answer: (A)

Locating Huànmén uses a posterior midline landmark and a precise lateral measurement. The vertical level is set by the spinous process of the fifth thoracic vertebra, and Huànmén lies 1.5 cun to the side of the lower border of that spinous process. This combination of a spinal level and a measured horizontal distance is how the point is consistently identified on the back.

So the correct description is 1.5 cun lateral to the lower border of the spinous process of T5. The other options describe locations at different landmarks (near DU-14, on the lower abdomen, or on the tongue) and do not correspond to Huànmén.