Sec. 1. (a) Subject to section 1.1 of this chapter, an individual who is at least eighteen (18) years of age may be adopted by a resident of Indiana:
(1) upon proper petition to the court having jurisdiction in probate matters in any county in Indiana; and
(2) with the consent of the individual acknowledged in open court.
(b) If the court in which a petition for adoption is filed under this section considers it necessary, the court may order:
(1) the type of investigation that is conducted in an adoption of a child who is less than eighteen (18) years of age; or
(2) any other inquiry that the court considers advisable;
before granting the petition for adoption.