The intersection of the planes defines 9 sub-regions:
a) Epigastric, umbilical, hypogastric, right and left hypochondriac, right and left lumbar, right and left inguinal
b) Right and left hypochondriac, epigastric, right and left lumbar, umbilical, right and left inguinal, hypogastric
c) Epigastric, hypochondriac, lumbar, umbilical, inguinal, hypogastric
d) Hypochondriac, lumbar, inguinal, umbilical, epigastric, hypogastric