Final answer:
The approximate standard deviation of returns of U.S. common stocks during the period between 1900 and 2017 was 19.7 percent. Hence, the correct answer is option (A).
Step-by-step explanation:
The approximate standard deviation of returns of U.S. common stocks during the period between 1900 and 2017 was 19.7 percent (option A). To calculate the standard deviation of returns, we would need the individual annual returns of the stocks over the given period. Since we don't have that information, we can refer to historical data and studies to make an estimate.
According to research and studies on the topic, the average annualized return of U.S. common stocks between 1900 and 2017 was around 9-10%. The annual standard deviation during this period ranged from about 15-20%. Therefore, option A (19.7 percent) is a reasonable approximation of the standard deviation of returns for U.S. common stocks during that time frame.