This year's "Eleventh" Golden Week, Mr. Zhang and his family traveled to Hainan Island. The most suitable things for Mr. Zhang to carry are: a. cash b. credit card C.

Test and analysis: it is neither convenient nor safe to carry a large amount of cash when traveling abroad, but foreign exchange can only be used if it is converted into cash. Checks can be divided into transfer checks and cash checks. Transfer checks can only be used for transfer, and cash checks can only be used for cash exchange, so credit cards are most suitable for carrying, which can be used for both withdrawal and consumption. The answer is B.

Comments: This topic examines the advantages of credit cards over cash, as well as the comparison between credit cards and checks. This question is close to students' life and easy to understand.