Which one of the following proviso clauses of Section 138, Negotiable Instruments Act requires notice…

The proviso to section 138 of the Negotiable Instruments Act sets three conditions: clause (a) presentation of the cheque within six months or its validity, clause (b) a written demand notice within thirty days of receiving information of dishonour, and clause (c) failure of the drawer to pay within fifteen days of receiving that notice. The fifteen-day period is therefore in "Clause (c)"; the proviso has no clause (d).