The correct answer is: can.
Genius is often defined as the ability to produce something original and of great value. Talent, on the other hand, is often defined as a natural aptitude or skill.
The statement “Genius does what it must, and talent does what it can” suggests that genius is driven by a higher purpose, while talent is more about following one’s own interests and abilities.
The option can is the most consistent with this interpretation. It suggests that talent is about doing what one is capable of, while genius is about doing what one is driven to do.
The options would, may, and should are all less consistent with this interpretation. They suggest that talent is about doing what one wants to do, what one is allowed to do, or what one is expected to do. This is not necessarily the same as doing what one is capable of.
In conclusion, the correct answer is can because it is the most consistent with the interpretation of the statement that genius is driven by a higher purpose, while talent is more about following one’s own interests and abilities.