A 50 foot run of electrical metalic tubing contains the following conductors: Four size 12 AWG Type THHN, four size 10 AWG Type THHN, four size 8 AWG Type THHN. What is the minimum allowable trade size EMT that can be used to enclose these conductors?

A 50 foot run of electrical metalic tubing contains the following conductors: Four size 12 AWG Type THHN, four size 10 AWG Type THHN, four size 8 AWG Type THHN. What is the minimum allowable trade size EMT that can be used to enclose these conductors?