Phone screening by Microsoft

I submitted my resume to MS Shanghai. After a week, I got a call. The tech recruiter apparently was reading through some routine questionnaire. As the first round, it just got more understanding based on the resume. Nothing interesting. At the end, she asked me why I switched my career to Computer Science later on while I was graduated in Automation from Tsinghua. This one is lame. It was more than 10 years ago. Even Mechanics can switch to CS, right?