First of all, explain that your job intention is a clerk, and then explain your ability and relevant work experience related to clerical work. Write it down in the basic information. You don't have to write "Why don't you do your own major" on your resume until the interview or the interviewer asks you himself. You can also say on your resume why you don't engage in your own major and show your enthusiasm for paperwork. It's usually written in the cover letter. I can help you with your resume.