AAAnswering questions in third person?

I think it is safest to write your answer to match the question if possible. So, if the question is "Describe substantive procedures the auditor should perform on the year-end trade payables of Greystone Co.", then the third person would seem better. Also don't waste time by starting each procedure's description with "The auditor should....". Have that at the start to introduce you set of procedures.

If the question said "Describe the further work you would do to,,,,,", then first person is a better match.

It seems that there has been a move away from answers in the first person to the third person. In many ways that's a pity because I believe that the first person helps you 'get into' the task much more successfully. You can imagine yourself there, describing in personal detail exactly what you would do and that is good for generating detail. You might like to work out what you would say in the first person ["I would reconcile the bank balance with the bank statement by...."] then write in the third ["The auditor should reconcile....."]

HTH