The funds of any medical service corporation subject to this chapter shall be invested only in securities in which assets of insurance companies may be authorized under the laws of this state. Nothing contained in this Code section shall be deemed to prohibit such corporation from investing its funds in a home office building or other tangible assets related to the operation of its business or from investing its funds in a wholly owned subsidiary agency corporation organized to solicit applications for insurance policies to be issued by an insurer authorized to transact life insurance in this state, subject to the same requirements, conditions, restrictions, and limitations as are applicable to such investments by life insurers.