If the Debtor fails to pay promptly when due to any person or entity monies which the Debtor is required to pay by reason of any provision in this Pledge Agreement, Pledgee may, but need not, pay the same and charge the Debtor’s account therefor, and the Debtor shall promptly reimburse Pledgee therefor. Any payments made by Pledgee shall not constitute: (a) an agreement by Pledgee to make similar payments in the future, or (b) a waiver by Pledgee of any default under this Pledge Agreement. Pledgee need not inquire as to, or contest the validity of, any such expense, tax, security interest, encumbrance or lien and the receipt of the usual official notice for the payment thereof shall be conclusive evidence that the same was validly due and owing.