What distinguishes an orphan under the IR4 category?

The correct choice is that an orphan under the IR4 category refers to a child coming to the U.S. for adoption. The IR4 visa category is specifically designed for children who are considered orphans under U.S. immigration law and who are being brought to the United States to be adopted by U.S. citizens. This category allows for the completion of the adoption after the child arrives in the U.S., which is essential in circumstances where the adoption process has not been finalized in the child's country of origin.

Each of the other options pertains to different aspects of the adoption process but does not accurately capture the defining characteristic of the IR4 category. For example, simply being adopted by a U.S. citizen or having been seen by the adoptive parent during the process does not specifically define the IR4 category. Additionally, the age of the child being over 16 years old does not apply, as this would typically fall outside the definitions of orphan status and adoptive processes under the IR4 criteria.

Thus, the ability of an orphan to be eligible under the IR4 classification is fundamentally linked to the conditions surrounding their arrival in the U.S. for the purpose of adoption, making the choice that identifies this context the most accurate.