Fill in the blank with a suitable preposition.
A bat flew ________ our heads when we were camping at night.
The preposition ‘over’ means above something. The phrase ‘flew over’ means something was flying just above some other object/person. Thus option A is correct. Whereas ‘on’ and ‘upon’ are both used to speak about placing an object or thing over something else. In the given context, the head is not a surface the bat can fly on. Thus options B and C are incorrect. On the other hand, ‘with’ is used to denote a tool used for performing an action or the company of someone. Since the head is neither of these, option D is incorrect.