Which of These Statements Regarding Price Changes Is Most Accurate

Which of these statements regarding price changes is most accurate?

A) Prices for tangible goods should change monthly, whereas service prices should change quarterly.
B) Changing a product's price too frequently creates antagonism among consumers, yet changing prices too infrequently makes them feel the company is not improving its product sufficiently.
C) Supermarkets should change their prices every week since customers are expecting new prices in the weekly flyers they receive in the mail.
D) Companies selling products online can instantly change their prices whenever the need arises.
E) Internet price changes are regulated by the Internet Fair Practices Act to protect consumers against price gouging.