C. To organize key-cards. D. To introduce a new banking service.

文章介绍了一种为青少年设计的新型银行。

These key cards can open only one lock and are issued to guest at check-in.

该级别为客人级别普通钥匙，一把钥匙只能开启相对应的一把锁，在登记入住时签发给客人。