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 ?
Answer: None of the above choices .This person is on drugs and feeling the effects .They are tripping over obstacles in their path .They are tripping over their own feet while trying to walk .