For every entrepreneur, starting his own business means risk, because as it can earn big money, it can also lose money. Also, business income may vary on a monthly basis. That is why there are various business predictions and studies, factors that influence the success of the business, but in spite of that, the market conditions are variable and bear the risk. So the loss of money with long working hours, are realities for an entrepreneur. However, this does not mean that in the future, the conditions will not change.
The answer is: a.