Could someone please explain the (3) sections that sentence is referring to? Section 220.61(B) seems to be the closest answer I can find.

36 unit apartment building, each dwelling unit supplied by single phase 120/240, 100 amp feeder panel. My question is can grounded conductor to EACH unit be reduced? According to section 220.61(B)(2) & 220.61(C)(1) I would think not.