(a) A bond on Form D shall be filed with each lease submitted for approval. Such bond shall be in an amount of not less than $5,000 for each quarter section or fractional quarter section covered by said lease: Provided, however, That one bond in the penal sum or not less than $50,000 may be filed on Form G covering all oil, gas and combination oil and gas leases not in excess of 10,240 acres to which Lessee is or may become a party.

(b) In lieu of the bonds required under paragraph (a) of this section, a bond in the penal sum of $150,000 may be filed on Form 5-5438 for full nationwide coverage of all leases, without geographic or acreage limitation, to which the Lessee is or may become a party.

(c) A bond on Form H shall be filed in an amount of not less than $5,000 covering a lease acquired through assignment where the assignee does not have a collective bond on form G or nationwide bond, or the corporate surety does not execute its consent to remain bound under the original bond given to secure the faithful performance of the terms and conditions of the lease.

(d) The right is specifically reserved to increase the amount of bonds prescribed in paragraphs (a) and (c) of this section in any particular case when the Superintendent deems it proper. The nationwide bond may be increased at any time in the discretion of the Secretary.