(1) Class A: Husband, wife, son, daughter, lineal ancestor, lineal descendant, brother, sister, stepchild, son-in-law or daughter-in-law. For the purposes of parts 3-5 of this chapter, a person who is related to the decedent as a result of legal adoption shall be considered to have the same relationship as a natural lineal ancestor, lineal descendant, brother, sister or stepchild; and
(2) Class B: Any other relative, person, association or corporation not specifically designated in Class A.