Who will select the Best Actress winner in Academy Awards?

M: Hey. Have you ever heard of Oscars, or Academy Awards?
W: Well, I should say I’ve done more than hearing of it. I know it quite well.
  Academy Awards or Oscars, are given every year in the United States by the Academy of Motion Picture Arts and Sciences for excellence in the creation and production of motion pictures. First presented in 1929, Oscars are among the film industry’s most desired prizes.
M: That seems very interesting. I wonder whether you know the principal categories for Academy Awards winners.
W: They include Best Picture, Best Director, Best Actor, Best Actress, Best Supporting Actor, Best Supporting Actress, Best Foreign Language Film, Best Special Effect, Best Sound, Best Musical Score, etc.
M: Oh, it seems quite inclusive.
W: But not many can get one during the whole life. And for most award categories, a maximum of five entrants are first nominated by the academy members who are in that particular field. That is, actors select actors, directors select directors and so on. From among these nominees, all academy members select the winners by secret ballot. The winners are publicly announced at a formal ceremony each spring.
M: Yeah. That’s really competitive, but what will each winner get? A certain amount of bonus?
W: No. Actually, a gold plated bronze human figure created by American sculptor George Stanley will be awarded to each winner.
M: Oh, I see. Thank you for your explanation. How do you manage to know all these?
W: Well, last semester I took a course in the history of films.