Answer:
C. By accident, Pablo trampled on the flowers in the garden with his boots.
Step-by-step explanation:
The sentence in the box has a misplaced modifier. The misplaced modifier suggests that Pablo's boots were placed in the garden while he trampled on the flowers. That does not really make sense. Therefore, the sentence needs to be rewritten to make it clear that "Pablo trampled on the flowers in the garden with his boots."