If the petition is approved the beneficiary is classified as follows:

(1) An unmarried beneficiary under the age of twenty-one is classified as the child of a United States citizen under section 201(b) of the Act;

(2) An unmarried beneficiary twenty-one years of age or older is classified as the unmarried son or daughter of a United States citizen under section 203(a)(1) of the Act; and

(3) A married beneficiary is classified as the married son or daughter of a United States citizen under section 203(a)(3) of the Act.