(a) An insurer that transacts any class or kind of insurance other than title insurance is not eligible for a license to transact the business of title insurance in this state, nor for the renewal thereof, nor shall title insurance be transacted, underwritten or issued by any insurer transacting or licensed to transact any other kind of insurance.
(b) An insurer shall not engage in the business of guaranteeing payment of the principal or the interest of bonds or mortgages.
(c) An insurer shall not engage in the business of guaranteeing the obligations of other persons other than issuing insured closing letters covering its agents in the normal course of business.