(a) The certificate of authority confers upon the insurer authority to transact in this State only the kind or kinds of insurance therein specified. No surety insurer shall be deemed thereby to possess power to act in capacity of executor, administrator, guardian, trustee, receiver, assignee, or agent, or in any other capacity than that of surety, notwithstanding contrary provisions in its charter.
(b) An insurer's valid and subsisting certificate of authority shall be prima facie evidence of its right to transact in this State the kind or kinds of insurance specified therein.