Answer: b. investing
Buying or selling stock is investing.
Explanation:
Investing refers to putting money into something which will later accumulate to profit that is more money in the nearest future.
Hence, investing in stock means that an individual has a share of ownership in a company which is of great benefit in the future because it generate profit. Stocks can be bought and sold at the stock exchange market with government regulations guiding the transaction in order to guide against fraudulent practices.