Answer: My Fair Lady
Julie Andrews had done an outstanding performance of portraying Eliza Doolittle in the play version of "My Fair Lady", but she was passed over for the movie lead, since it was felt that she was not well known enough yet. Ironically, both of these movies went up for Academy Awards, and it was Julie Andrews who won the Academy Award for best actress. Audrey Hepburn, who played the movie part of Eliza Doolitte, had not even been nominated. The other choices were movies that Julie Andrews starred in later on in her career.