enrich, your question seems to have been overlooked.
IF anyone makes a takeover offer for AVB, they will make an offer for both the shares and the listed options. So, if it's a cash offer, you can expect Xc per share and (X-1.5)c per options. Or if it's a scrip offer, they will offer shares to those values.
Had to dig deep into my memory banks for an example but did come up with RPT which was taken over in 1996. As you can see from the asx release in the link below, in this case Mega offered 20 Mega shares for every 574 Redport shares or 20 Mega shares for every 894 listed options.