According to lips-wiersma and morris, the four sources of meaningful work include serving others, unity with others, and expressing one's full potential.

I believe the answer is : developing and becoming self

 developing and becoming self refers to the act of pursuing one's own desire/interest rather than conforming to what society expected them to be. By choosing a career path that is aligned with our interest, our life would most likely lead to greater satisfaction compared to the careers that are not.