Primary Purpose of a "Sneak Preview" of a Film Prior

primary purpose of a "sneak preview" of a film prior to its release is to

A) rate the performances of the individual actors and actresses for possible Oscar nominations.
B) rate the work of the director and producer for possible Oscar nominations.
C) evaluate the effectiveness of product placements within the film.
D) compare the final film to the original screenplay.
E) identify necessary changes prior to final editing and release to increase the film's likelihood of success.