【单选题】

What does the author mean by the statement "Although price wars do occur, in which all companies offer substantial savings to customers, a somewhat similar tendency to raise prices simultaneously is also usual"
A．It is not unusual for all companies to increase prices at the same time.

B．It is common for companies to compete for customers by lowering prices.
C．Customers may lose money when companies have price wars.
D．Prices are lower during price wars, but they are usually higher afterward.