Answer: His primary reason for this choice is his DESIRE TO SERVE OTHERS.
Explanation: In his bid to serve others, Jon has chosen teaching as a profession. Disturbed by the problems of contemporary America such as the erosion of the family, the increasing violence in our cities, and the hardships of poverty, he has chosen the path of becoming a teacher. This exactly what leaders in civil administration do such as politicians. In a bid for change, they have to serve others, the masses.