Insurance Companies Tend to Have a Stock Market Price at a Discount

Insurance companies tend to have a stock market price at a discount to the average market price (price/earnings ratio) .Which of the following is not a likely reason for this relatively low market value?

A) Insurance is a highly regulated industry.
B) The insurance industry has substantial competition.
C) The accounting environment likely contributes to the relatively low market price for insurance company stocks.
D) The nature of the industry leads to standards that provide for much judgment and possible manipulation of reported profit.
E) Insurance companies typically have a high return on common equity.