58.0.3. Unless the context otherwise requires, a taxpayer is deemed to exercise identical rights to acquire securities under agreements referred to in section 48(a) where the taxpayer has designated an order for the purposes of paragraph a of subsection 12 of section 7 of the Income Tax Act (Revised Statutes of Canada, 1985, chapter 1, 5th Supplement), in the order so designated; and
(b) in any other case, in the order in which those rights first became exercisable and, in the case of identical rights that first became exercisable at the same time, in the order in which the agreements under which those rights were acquired were made.