A guardian legally holding funds or assets belonging to or for the benefit of a minor may with the approval of the district court or other court in which such estate is pending, invest such funds or assets or any part thereof, in single premium life, single premium endowment, or single premium annuity contracts of legal reserve life insurance companies as are duly licensed and qualified to transact business within this state.
Okla. Stat. tit. 30, § 2-110