According to "A Letter to my Daughter",what can be inferred from the author’s quitting from various jobs and starting his own business?

A、He wanted to have real control of his life and live the life that he wanted to.
B、He was not satisfied with his former employers and wanted to be with his family more often.
C、He realized he was not suitable for working in the academic world or in corporations.
D、He wanted to go to China and worked for Google in order to start his own business.