Could be false. It is possible for a song that is not a hit to be played on the radio, and those songwriters would still receive some revenue.

Could be false. It is possible for a writer who hasn't written a hit to write songs for movie soundtracks. We know that sometimes writers of hit songs are asked to write songs for movie soundtracks, but this leaves open the possibility that other writers also can be asked to write songs for movie soundtracks.

Must be true. The stimulus tells us that songs written for movie soundtracks frequently become hits. Since hit songs are played on the radio thousands of times, it must follow that some songs written for movie soundtracks are played on the radio thousands of times.

Could be false. Although we know that writers who are asked to write movie songs often decline due to the way they are paid for the movie songs, we don't know that most songwriters prefer continued income over single up-front payments. Perhaps most songwriters would be fine with single up-front payments even if some people who are asked to write movie songs are not.

Could be false. We don't know that some songwriters have no other way of earning money. Although we know that songwriters get much of the money they earn from radio airplay, that does not mean this is their only source of money.