【单选题】

Passage 2:Hong Kong has about 40 public beaches. Some of the beaches are among the best in the worlD、People can go there for a swim. You can go to most of them by bus. To go to some of the beaches you must take a boat. There are clothes changing rooms and places to buy food and drink on most of the beaches.You will swim there without danger if you remember these instructions: 1) Never swim alone.2) Never swim after a meal or when you feel hungry or tireD、3)Don’t stay in the water too long.4) Never go out in a boat if you can not swim.Remember:

A、red flag means that it is dangerous for anyone to go into the water.
A、blue flag means that it is dangerous for children. We can reach ________ by bus.
A、all the public beaches
B．any public beach
C．only a few public beaches
D．most of the beaches