I do think it is C because it will always stay the same "Fixed"
When you see a sentence not make sense it's usually because you are leaving out important words or mixing them up in the wrong way in that sentence so due to this knowledge a dangling modifier would be C.
Answer:
While driving to the airport, in an effort to distract herself from the thoughts of her ageing mother, the poet looks at the young trees 'sprinting'. The trees seem to be running past the moving car. The sprinting of the trees symbolises the rapidly passing years of human's life from childhood to old age
Explanation: