Where would you get a pen if you do not have one?\nOptions:\n- briefcase\n- desk drawer\n- friend's house\n- pocket\n- sidewalk Let's think step by step:
User
One has to borrow a pen if one does not have it. People tend to borrow stuff from their friends. One goes to a friend's house if one wants to borrow a pen. So, the answer is friend's house.
Assistant