Answer: a. limited liability for investors.
Explanation:
Companies with shares on the stock market are public limited companies. Their limited nature mean that an investor's losses are limited to the amount that they invest in the company and nothing more.
If Josie invests $1,000 into the stock of a company and the company decides to engage in unethical business practices which causes its stock price to plummet to almost zero, the only money that Josie will lose is the $1,000 that she invested.