Should he obey his father and give up his studies in order to work in business?

Praise be to Allah.

The son should combine two good deeds, by both seeking knowledge and helping his father in his business. If his father insists on forcing his son to give up seeking knowledge and work in business, then he may not obey him in that and this is not considered to be disobedience towards his father. 

And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote.