I received an offer at energy company to do a multi term co-op with them. However, at the time I signed up with them I thought I would be doing accounting, but this company decided to put me in payroll. I have stopped learning in this position after 2 months and I am not doing anything I can use as experience for the CPA license. It extremely boring for me and half the time I am not doing anything. The downside of working here is that it takes an hour to get to work and I feel I will get stuck in payroll.
However, I received an offer to work at a public accounting firm that is doing tax. I am really interested in tax. This position pays more (almost $10 more per hour), five minute drive from my home and I can gain experience for the CPA license. Is it acceptable resign after one semester? What will be the best way of resigning from my position? I just feel bad because they had trained me for this position, but I understand that I can get fired at any point since it is an at will employment.