Final answer:
A stock provides a variable rate of return based on factors such as market conditions, company performance, and investor demand for the stock.
Step-by-step explanation:
A stock provides a variable rate of return. The rate of return on a stock represents the percentage gain or loss an investor has experienced on their initial investment. It can vary depending on factors such as market conditions, company performance, and investor demand for the stock.
For example, if an investor buys a stock at $50 per share and sells it a year later at $60 per share, they have a rate of return of 20%.
So, the correct answer is b) Variable rate.