Final answer:
In Shia Islam, the most important qualification for choosing the rightful leader of Islam is being known for noble character.
Step-by-step explanation:
In Shia Islam, the most important qualification for choosing the rightful leader of Islam would be B) Known for his noble character. While all the options mentioned in the question are important, Shia Muslims give significant importance to the individual's character and moral qualities. Being known for noble character ensures that the leader is virtuous, ethical, and upholds the values of Islam.