The maple wears a gayer scarf.
Means that it's leaves are changing at it is "wearing" colorful clothing. wears is personification.
The field a scarlet gown
It is autumn. The field is now covered with scarlet leaves from the maple and other vegetation.
A
It is anything but nonsense. It is has a clear and poetic turn to the lines quoted. A is wrong.
B
The personification in the lines quoted is the poem. wearing, scarf's and gowns are central to what the poem is saying. B is incorrect.
C
No this is just wrong. The speaker is not hallucinating. What he sees is what there is. The speaker just has a different way of expressing it.
D
This is the answer. The speaker is talking about seasonal change.
