Final answer:
At level 20, barbarians in Dungeons & Dragons gain the abilities Primal Champion, which increases certain ability scores, and Indomitable Might, which can replace strength check totals.
Step-by-step explanation:
At level 20, barbarians in the game Dungeons & Dragons gain two unique abilities: Primal Champion and Indomitable Might. The Primal Champion ability increases a barbarian's strength and constitution scores by 4, and the maximum for these scores becomes 24. Additionally, Indomitable Might ensures that if the total for a Strength check is less than the barbarian's Strength score, they can use that score in place of the total.
Answer: C) Primal Champion and Indomitable Might