Read the following article and select the best answer. Article: Do you know Fei Junlong and Nie Haisheng? Fei Junlong was born in 1965. He is a Chinese astronaut selected as a member of the Shenzhou program. He was born in Jiangsu and joined the People's Liberation Army Air Force in 1982 at the age of 17. And since then he has only returned home six times. As a fighter pilot , he was selected to an astronaut in 1998. He married Wang Jie in 1991 and has one son. Nie Haisheng was born in September 1964. He is also a Chinese astronaut selected for the Shenzhou program. He is from Hubei. After graduating from high school he joined the People's Liberation Army Air Force, and became a fighter pilot. In 1998 he was selected for the astronaut program. He was one of the three astronauts who were in the final group to train for the Shenzhou 5 fight. Yang Liwei was also picked out for the flight, with Zhai Ahigang. On September 23,2005 it was reported that Zhai and Nie would be one of the three pairs of astronauts who would be in the final training for Shenzhou 6. But in the end, Fei and Nie were chosen, and Zhai missed his chance to space again. Nie Haisheng got married to Nie Jielin and has an 11-year-old daughter. Question: When did Nie join the army? - In 1982. - In 1998. - In 1991. - After his graduation from high school.
The answer to this question is:
After his graduation from high school.