Mortgagor shall not be required to pay, discharge or remove any Imposition or any Lien so long as Mortgagor shall in good faith contest the same or the validity thereof by appropriate legal proceedings which shall operate to prevent the collection of the Lien or Imposition so contested and the sale of the Mortgaged Property, or any part thereof, to satisfy the same, provided that Mortgagor shall, prior to the date such Lien or Imposition is due and payable, have given such reasonable security as may be demanded by Mortgagee to insure such payments plus interest or penalties thereon, and prevent any sale or forfeiture of the Mortgaged Property by reason of such nonpayment. Any such contest shall be prosecuted with due diligence and Mortgagor shall promptly after final determination thereof pay the amount of any such Lien or Imposition so determined, together with all interest and penalties which may be payable in connection therewith. Notwithstanding these provisions Mortgagor shall (and if Mortgagor shall fail so to do, Mortgagee, may but shall not be required to) pay any such Lien or Imposition notwithstanding such contest if in the reasonable opinion of Mortgagee, the Mortgaged Property shall be in jeopardy or in danger of being forfeited or foreclosed.