Offers for leasing may be made in writing and such bids must be opened at the time of the leasing and bids may be offered orally at the time of the leasing. Such bids must be made upon the basis of acceptance of a lease upon the rental basis herein provided, plus such bonus as the bidder may offer. The leasing agency may reject all bids and no bid may be accepted unless the bidder shall, at the time of the leasing, tender or pay to the leasing official an amount equal to the first year‘s rental for such oil and gas rights, plus any bonus offered for such lease.