A famous singer recently won a lawsuit against an advertising firm for using another singer in a commercial to evoke the famous singer s well-known rendition of a certain song. As a result of the lawsuit, advertising firms will stop using imitators in commercials. Therefore, advertising costs will rise, since famous singers services cost more than those of their imitators. The conclusion above is based on which of the following assumptions？

A. Most people are unable to distinguish a famous singer"s rendition of a song from a good imitator" s rendition of the same song.
B. Commercials using famous singers are usually more effective than commercials using imitators of famous singers.
C. The original versions of some well-known songs are unavailable for use in commercials.
D. Advertising firms will continue to use imitators to mimic the physical mannerisms of famous singers.
E. The advertising industry will use well-known renditions of songs in commercials.