(oil and gas leases granted defendant (lessee) right to match any third-party offer to lease land for purposes of oil and gas exploration; question was whether on defendant’s refusal to match third-party offer plaintiffs (landowners) could terminate defendant’s lease and enter into new lease with third-party immediately; trial court rejected plaintiffs’ argument; pertinent language granted defendant preferential right and did not impose duty on defendant; no right to terminate lease granted by clause language; trial court decision affirmed).