the word only indicates that "an hour" is considered a short time period for the flower, and so it represents "the youth" of it being a flower before it becomes like the rest
Explanation: In literature, the theme is the underlying message of a story, it is what critical belief about life is the author trying to convey in the writing of a novel, play, short story or poem. Usually this belief, or idea, is universal and transcends cultural barriers. From the given options, the line of the poem that expresses the theme that youth passes quickly, is option B: but only so an hour, because it is comparing the youth to a flower that only last an hour (a short period of time).
