Read the following context and choose the best option to answer the question.
Context: But I had little choice , and we had to go . Looking back at it now , I was tripping my bastard arse off , it 's a wonder I did n't get hit by a car , or sectioned or something . These two cunts walk at practically running speed , so I ' m struggling at the back , with my shin splints and seeing all the same streets as I normally do , but they look much better tonight , much more sparkly and shit .
Question: What does the person mean by tripping ?
Options: 
A. None of the above choices .
B. This person is on drugs and feeling the effects .
C. They are tripping over obstacles in their path .
D. They are tripping over their own feet while trying to walk .


B