If you have stayed less than two years in your last job, it is considered as short period. You have to be prepared to give an explanation for this question. But do not be defensive or feel sorry about staying for short period in an organization.
Your can always justify an answer with your career goals.
Sample answer is:
I have joined abc organization as software engineer. I was assigned to work on deployment automation team. I learnt the work in first three months and became a strong contributor in that area. For my long-term career goal of becoming an architect, I wanted to work on business domain of Mobile commerce. In abc organization, current focus of technology was not in growing Mobile commerce. So I decided to find opportunities outside ABC organization to learn and work on Mobile commerce. I find your organization is taking many initiatives in this area. I am excited to work with your organization on this area.