⟩ Which other careers are you considering?
The obvious answer would be careers in banking and insurance and other finance areas, but it is OK to mention any career here as long as you can argue your case effectively e.g. by demonstrating that the skills required are similar to those of an accountant.
Interviewers will be looking for evidence that you have analyzed your skills and interests in a logical manner when coming to a career decision, and also for signs of your commitment to accountancy.
However, in an interview you do not HAVE to tell the truth, the whole truth and nothing but the truth. If you admit to also applying for highly-competitive areas such as journalism or the Diplomatic Service, the interviewer is likely to assume that accountancy is your second choice. Similarly, you might find the interviewer challenging your interest in business if you said that social work or nursing was also an option.