Suppose Dylan wants to calculate the historical variance of a company's returns over the past ten years. How would you explain to Dylan what it is? O A. The squared summation of the differences between the actual returns and the average geometric return. B. The average difference between the annual returns and the average return for the period. C. The average squared difference between the actual returns and the arithmetic average return. D. The difference between the arithmetic average and the geometric average return for the period. E. The average squared difference between the arithmetic and the geometric average annual returns