Answer:
D) Before leaving for school, I decided to eat a good breakfast.
Step-by-step explanation:
A modifier is a word or a phrase which, as the name suggests, modifies a certain word.
Dangling modifier is a modifier when its modifying word is left out of the sentence, making it sound confusing.
On the other hand, a misplaced modifier is a modifier modifying the wrong worg, changing the meaning of the sentance.
In sentence A), the subject of the sentence (the one who drives) is left out, so we may be led to think that the trip was driving, which is, of course, completely illogical.
In sentence B), again, we don't know who made a long run; it certainly wasn't the lemonade, as the sentence might suggest.
In sentence C), it is highly unlikely that the man's beard weighs 200 pounds; it modifies the beard instead of the man.
And, finally, sentence D) seems correct, there is a subject ( I ) who has to leave for school but decides to enjoy the breakfast first; no confusion whatsoever.