Lessee is hereby given the option to extend the primary term of this lease for an additional two (2) years from the expiration of the original primary term hereof. This option may be exercised by Lessee at any time during the last year of the original primary by paying the sum of ___________ and No/100 Dollars ($______.00) per net mineral acre to Lessor or to the credit of Lessor in the _________________________________Bank, at ________________________ (which bank and its successors are Lessor's agents and shall continue as the depository regardless of changes in ownership of said land.) This payment shall be based upon the number of net mineral acres then covered by this lease and not at such time being maintained by other provisions hereof. This payment may be made by the check or draft of Lessee mailed or delivered to Lessor or to said bank at any time during the last year of the original primary term hereof. If such bank (or any successor bank) should fail, liquidate or be succeeded by another bank, or for any reason fail or refuse to accept payment, Lessee shall not be held in default for failure to make such payment until thirty (30) days after Lessor's delivery to Lessee of a proper recordable instrument naming another bank as agent to receive such payment. If, at the time this payment is made, various parties are entitled to specific amounts according to Lessee's records, this payment may be divided between said parties and paid in the same proportion. Should this option be exercised as herein provided, it shall be considered for all purposes as though this lease originally provided for a primary term of five (5) years. In the event this lease is being maintained by any other lease provisions at the expiration of the primary term, Lessee shall have a period of thirty (30) days from the date this lease ceases to be so maintained within which to exercise this option.