; or (2) in the case of a ticket purchased with cash or another form of payment, not later than 20 days after the earliest date the refund was requested as set forth in subsection (f). (c) Alternative to refund An air carrier and a foreign air carrier may offer a voucher, credit, or other form of compensation as an explicit alternative to providing a refund required by subsection (a) but only if— (1) the offer includes a clear and conspicuous notice of— (A) the terms of the offer; and (B) the passenger's right to a full refund under this section; (2) the voucher, credit, or other form of compensation offered explicitly as an alternative to providing a refund required by subsection (a) remains valid and redeemable by the consumer for a period of at least 5 years from the date on which such voucher, credit, or other form of compensation is issued; (3) upon the issuance of such voucher, credit, or other form of compensation, an air carrier, foreign air carrier, or ticket agent, where applicable, notifies the recipient of the expiration date of the voucher, credit, or other form of compensation; and (4) upon request by an individual who self-identifies as having a disability (as defined in section 382.3 of title 14, Code of Federal Regulations), an air carrier, foreign air carrier, or ticket agent provides a notification under paragraph (3) in an electronic format that is accessible to the recipient. (d) Significantly delayed or changed flight defined In this section, the term significantly delayed or changed flight includes, at a minimum, a flight where the passenger arrives at a destination airport— (1) in the case of a domestic flight, 3 or more hours after the original scheduled arrival time