Which of the Following Statements Is False

Which of the following statements is false?

A) We measure the degree of estimation error statistically through the standard error of the estimate.
B) When focusing on the returns of a single security, its common practice to assume that all dividends are immediately invested at the risk-free rate.
C) We estimate the standard deviation or volatility as the square root of the variance.
D) We estimate the variance by computing the average squared deviation from the average realized return.