If a youth has purchased a general season elk tag (Unit 39 Nov.1-Nov.9) are they allowed to harvest either sex?

A resident youth (ages 10-17) can hunt both the A and B seasons of an elk zone.  However, the rules of each season must be followed as specified in the seasons and rules. Per your example, the B tag season on the Boise River zone tag is for antlered only.  Therefore, either sex would not be allowed during the period of November 1-9.