Passage Summary: Songwriters usually get paid every time their song plays on the radio, but movie songs often pay a one-time fee instead, which can be less profitable if the song becomes a massive hit.

Reasoning: Songwriters earn money per radio play for hits, but movie soundtracks often pay a flat fee instead of royalties, leading some writers to turn down movie work despite the high likelihood of those songs becoming hits.

Analysis: To find the statement that must be true, we need to synthesize the facts about payment structures. We are told that some writers decline movie deals because they prefer radio royalties over flat fees, even though movie songs often become hits. This implies that for these writers, the potential income from per-play radio royalties is expected to be higher than the single payment offered by the movie studio. Look for an answer that reflects this financial trade-off or the fact that movie hits don't always result in the same type of long-term revenue as standard radio hits.