Answer: D) to raise lots of capital (money)
There is (a lot of) risk whenever it comes to producing a product or offering a service. One way to reduce the risk is to spread it out to many people, which in this case would be shareholders. One of the first corporations involved people pooling their money together so that ocean voyages could happen. Beforehand, only the very very wealthy could attempt such a feat and usually it had backing of royalty of some kind.
In contrast, a small business with a single owner (or a few owners or family owned) is not a corporation. There's a small number of owners that the risk is more concentrated in those few individuals.