Identify the sentence in which the underlined clause is a noun clause that functions as the subject of the sentence. Whatever movie is playing is acceptable to us! We ordered the healthier popcorn that was air-popped. The best place to see a movie is at the drive-in.

Hi, the correct answer would be - Whatever movie is playing is acceptable to us, where "whatever movie is playing" is the subject of the whole sentence. The other examples cannot be the correct choice, as in the second example the noun clause "the healthier popcorn that was air-popped" is not a subject, it is an object. And in the final example, "the best place to see a movie" is also an object.