Final answer:
Barbarians in D&D gain more rage charges at odd-numbered levels, receiving additional rages at levels 3, 6, 9, 12, 15, and 17, leading up to a total of six rages at level 20.
Step-by-step explanation:
In the role-playing game Dungeons & Dragons (D&D), which the Advanced Placement (AP) program sometimes includes in its curriculum for educational purposes, barbarians gain additional rage charges as they level up. Specifically, barbarians receive an increase to their number of rage charges at odd-numbered levels.
Therefore, the correct answer to the question, 'At what levels do barbarians gain more rage charges?' is B) Odd-numbered levels. Barbarians start with two rages at 1st level and gain additional rages at 3rd, 6th, 9th, 12th, 15th, and 17th levels, leading up to a total of six rage charges at 20th level in the core rules of D&D 5th edition.