O-levels were exams taken by 15 and 16-year-olds.
The Fourth Doctor claimed to have received an O-level in Starship Weaponry, while attending Gallifrey Comp. (COMIC: Doctor Who and the Star Beast [+]Pat Mills and John Wagner, DWM Comics (Marvel Comics, 1980).)
Dodo Chaplet did not take history for her O-levels. (AUDIO: Fugitive of the Daleks [+]Jonathan Morris, The First Doctor Adventures (Big Finish Productions, 2024).)
Ace failed her chemistry O-levels, despite being skilled at it. (TV: Dragonfire [+]Ian Briggs, adapted from Seventh Doctor Audition Tapes (Andrew Cartmel), Doctor Who season 24 (BBC1, 1987).) She also took art O-levels with Miss Parkinson. (AUDIO: Dust Breeding [+]Mike Tucker, Main Range (Big Finish Productions, 2001).)
Yvonne Hartman did an O level in biology at comprehensive school. (AUDIO: The Rockery [+]Error: Code 2 - no data stored in variables, cache or SMW.)