An additional source of revenue for a corporation beyond product or service sales is:

a) Licensing

b) Stocks

C) Real estate

d) All of the above

Your answer is all of the above.

Explanation:

Each one of these options is generally profitable for most corporations. Sometimes there are recessions (like right now on our 5th week of the coronavirus outbreak) where Real Estate and Stocks can lose value but for the most part these are ways a business makes money.