GMAT Sentence Correction (SC) | Re: The recent surge in the number of airplane flights has

B changes meaning.
Intention - 55 % more delays i.e. If previously there were 100 delays now it is 155 delays.
B says - previously if the delay was 100 min now it is 155 minutes delay. :D .

So Answer must be E. . Hope you understood- Hit GMAT like you mean it. All the best.

---