The correct answer is - B. a variety of companies.
The investors have the tendency to be investing money in multiple different companies in order to minimize the risk of loss of money. This tactic, in general, works relatively well and provides stability when it comes to investment and profit. The reasons why this a good tactic for the investors is that if some of the companies starts to decline, they also have profit from the others that are prospering, so the chances of losing money are very low.