Notwithstanding any restrictions on investments contained in any laws of this state, the state and all public officers, municipal corporations, political subdivisions, and the public bodies, all banks, bankers, trust companies, savings banks and institutions, building and loan associations, savings and loan associations, investment companies, and other persons carrying on a banking business, and all insurance companies, insurance associations, and other persons carrying on an insurance business, may legally invest any sinking funds, moneys, or other funds, belonging to them or within their control, in any bonds or other obligations issued by an agency, as herein defined, and those bonds and other obligations shall be authorized security for all public deposits; it being one of the purposes of chapters 31 — 33 of this title, to authorize all persons, firms, corporations, associations, political subdivisions, bodies, and officers, public or private, to use any funds owned or controlled by them including, but not limited to, sinking, insurance, investment, retirement, compensation, pension, and trust funds, and any funds held on deposit, for the purchase of any bonds or other obligations; provided, that nothing contained in chapters 31 — 33 of this title, shall be construed as relieving any person, firm, or corporation from any duty of exercising reasonable care in selecting securities.