Office of Population Affairs
The Office of Population Affairs ( OPA ) is part of the Office of Public Health and Science in the United States Department of Health and Human Services ( HHS ) . 
<triplet> Office of Population Affairs <subj> Office of Public Health and Science <obj> parent organization <triplet> Office of Public Health and Science <subj> United States Department of Health and Human Services <obj> parent organization <triplet> United States Department of Health and Human Services <subj> Office of Public Health and Science <obj> subsidiary