boom or bust, it is possible to extend the options if the BOD wish to. Check out Continental Coal (CCC) who just happened to be dual listed with AIM also. They extended their options (CCCO) another 2 years at no cost to current option holders by issuing new perspectus with ASX.
ASX ann dated 5/6/13 "Offer for new listed options"
Unfortunately the story was not a good one for them as they are in voluntary suspension.