Hello Lawrence, it seems we have a choice either use the parents who adopted or use the biological.
In my case a family member I used the parents who adopted him but in the edit mode - clicked definitely not biological - they raised him from three months old, so his entire life these were his parents. What I did though was added a link within his profile to his biological mother (yet to find out his father).
What happened was something seemed odd, so purchased the birth certificate which actually confirmed what I had thought. He grew up alongside step siblings not knowing he was adopted and he died very young (WW I), even the register for deaths of soldiers listed his parents (the adoptive).