$($id:$123966)$

NEC Reference

An apartment complex is supplied by a $208$Y$/120-$volt, $3-$phase, $4-$wire, wye service. A $3-$wire, $208$Y$/120-$volt, $150-$ampere feeder supplies a $150-$ampere rated panelboard installed in an individual dwelling unit of the apartment building to supply the entire load of the individual unit. The conductors are installed in a location with an ambient temperature of $110F.$ What is the minimum size THWN$-2$ ungrounded feeder conductor required to supply the individual dwelling unit?

a$.2$ AWG THWN$-2$

b$.1$ AWG THWN$-2$

c$.1/0$ AWG THWN$-2$

d$.2/0$ AWG THWN$-2$