The price of the share of a company becomes 16 times in 4 years. The average annual rate of increase is:

Average annual rate of increase = (final value – initial value) / initial value * 100%

In this case, the final value is 16 and the initial value is 1. Therefore, the average annual rate of increase is:

Average annual rate of increase = (16 – 1) / 1 * 100% = 1500%

This means that the price of the share has increased by an average of 1500% each year.

Option (a) is incorrect because it is the percentage increase in the price of the share over the entire 4-year period. Option (b) is incorrect because it is the percentage increase in the price of the share over the first year. Option (d) is incorrect because it is not a possible answer.