What do you need to be to learn hard concepts?
Options:
- copy
- intelligent
- improved performance
- empowering
- have more knowledge
Let's think carefully first. Step-by-step reasoning process:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Intelligent means having or showing intelligence, especially of a high level. You need to be intelligent to learn hard concepts. So the final answer is intelligent.