Thirty years ago, the percentage of the British people who vacationed in foreign countries was very small compared with the large percentage of the British population who travel abroad for vacations now. Foreign travel is, and always has been, expensive from Britain. Ttherefore, British people must have, on average, more money to spend on vacations now than they did 30 years ago. The argument requires assuming which one of the following? ['If more of the British people of 30 years ago had had enough money to vacation abroad, more would have done so.', 'If foreign travel had been less expensive 30 years ago, British people would still not have had enough money to take vacations abroad.', 'If the percentage of British people vacationing abroad was lower 30 years ago, then the British people of 30 years ago must have spent more money on domestic vacations.', 'If British people are now wealthier than they were 30 years ago, then they must have more money to spend on vacations now than they did 30 years ago.']