The space agency believes that excellent astronauts should have three requirements: first, they must have rich knowledge; second, they must have proficient technology; third, they must have strong will. Existing A, B,  C and D Four outstanding pilots signed up for the election. Known: 1.A and B have the same level of willpower 2.B and C have the same level of knowledge 3.C and D are not all knowledgeable 4.Three of the four people are knowledgeable, two of them are strong willed, and one is skilled. The space agency found only one of them  meets all the requirements of an excellent astronaut.
Option D fully meets the requirements of an excellent astronaut.