XmVaCreateDropDown(3) on Linux
The text 45698384a8f5, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A DropDown widget convenience creation functions. "XmVaCreateDropDown" "XmVaCreateManagedDropDown" "creation functions" "XmVaCreateDropDown"