You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: DIRECTORS 
Clue: Biographer Donald Spoto says that as a schoolboy, this "Vertigo" director was nicknamed "Cocky"
alfred hitchcock

Category: THE ENGLISH MONARCH SPEAKS 
Clue: She warned her council who were against her moves on Mary Queen of Scots, "I will make you shorter by a head"
elizabeth i

Category: SICKNESS & HEALTH 
Clue: Although arthroscopic surgery can be performed on many joints, it is most often done on this one

the knee