When joining two independent clauses with a coordinating conjunction, where do you place the comma?

Ron and nick chose to start their own businesses. ron wanted to start an ice cream shop, and nick wanted to launch a television manufacturing company. ron and nick had equal amounts of funds on hand and no government regulations restricting them. months later, however, ron has already set up his business, while nick is still struggling to raise additional funds to build a factory. what was the main factor that affected nick’s business? a. an irrelevant business idea b. low demand for tvs in his country c. high start-up costs d. lack of labor economics