Questions 1 to 5 are based on an interview. According to the conversation when are all the big shops closed

A．the kidnappers consider it a pleasure to do harm to the victims
B．some rebel groups financed themselves through kidnapping
C．foreign countries have invested little in the Third World
D．the kidnappers know that frequently an insurance company will pay out big for the hostages

A．A shortage of research funds.
B．A reluctance to acquire advanced mathematical skills.
C．An insufficient knowledge of computer languages.
D．An unwillingness to work cooperatively with mathematicians.