Given that Aruba and Iceland can switch between producing coolers and producing radios at a constant rate.
Aruba’s opportunity cost of one cooler is  ______.
A、0.4 radio and Iceland’s opportunity cost of one cooler is 0.25 radio
B、0.4 radio and Iceland’s opportunity cost of one cooler is 4 radios
C、2.5 radios and Iceland’s opportunity cost of one cooler is 0.25 radio
D、2.5 radios and Iceland’s opportunity cost of one cooler is 4 radios