(a) In general
(b) Functional currency
(1) In generalFor purposes of this subtitle, the term “functional currency” means—
in the case of a qualified business unit, the currency of the economic environment in which a significant part of such unit’s activities are conducted and which is used by such unit in keeping its books and records.
(2) Functional currency where activities primarily conducted in dollars
(3) ElectionTo the extent provided in regulations, the taxpayer may elect to use the dollar as the functional currency for any qualified business unit if—