An american factory needs to buy special tools which are made only by companies in either switzerland or britain. the tools made in switzerland cost 100 francs apiece; the ones made in britain cost 100 pounds each. based on the exchange rates below, what should the factory do?

u. s. dollar comparison
$1.00 u. s. = 0.80 swiss francs
$1.00 u. s. = 0.67 pounds

buy the tools from britain
make the tools themselves
wait until the exchange rate gets better
buy the tools from switzerland