(b) Not less than sixty percent of the amount of the required minimum capital or surplus to policyholder investments shall consist of the types specified in paragraphs one and two hereof:
(1) Obligations of the United States or of any agency thereof provided such agency obligations are guaranteed as to principal and interest by the United States.
(2) Direct obligations of this state or of any county, district or municipality thereof.
(3) Direct obligations of any state of the United States.
(4) Obligations secured by first mortgage loans which meet the standards specified in paragraph four of subsection (a) of section one thousand four hundred four of this article on property located in this state.