Fill in the blank with a suitable preposition.
People have been waiting in the theatres _______ early morning, to buy Bahubali tickets.
The given sentence provides information about the beginning of the waiting period. Therefore the preposition ‘since’ is an apt answer because ‘since’ is used to speak about the starting point of an action. In addition to this, ‘since’ is always used in a sentence that is in the perfect tense. Thus option A is correct. ‘Under’ is used to mean less than, whereas ‘within’ is used to refer to a period within which an action is completed. Both of these answers are unsuitable in the given context, hence options B and C are incorrect. Similarly, ‘on’ is used to denote a day or date which is once again irrelevant. Thus option D is incorrect.