In general

Notwithstanding section 6501, the limitation on the time period for the assessment of any amount attributable to a credit claimed under this section shall not expire before the date that is 6 years after the latest of—

(A) the date on which the original return which includes the calendar quarter with respect to which such credit is determined is filed,

(B) the date on which such return is treated as filed under section 6501(b)(2), or

(C) the date on which the claim for credit or refund with respect to such credit is made.