The correct answer is: Only conclusion II follows.
The first statement is “All film stars are playback singers.” This means that every film star is a playback singer. The second statement is “All film directors are film stars.” This means that every film director is a film star.
The first conclusion is “All film directors are playback singers.” This conclusion does not follow from the statements. The statements only say that all film stars are playback singers, and that all film directors are film stars. They do not say that all film directors are film stars because they are film stars. It is possible that there are film directors who are not playback singers, but who are film stars for other reasons.
The second conclusion is “Some film stars are film directors.” This conclusion does follow from the statements. The statements say that all film stars are playback singers, and that all film directors are film stars. This means that there must be some film stars who are also film directors.
Therefore, the only conclusion that follows from the statements is “Some film stars are film directors.”