Sociologist Alton Okinaka sits on the review board tasked with adding new sites to the Hawaii Register of Historic Places, which includes Pillianhale Heiau and the 'Opaeka'a Road Bridge. Okinaka doesn't make such decisions ________ all historical designations must be approved by a group of nine other experts from the fields of architecture, archaeology, history, and Hawaiian culture.

Which choice completes the text so that it conforms to the conventions of Standard English?