Fill in the blank with a suitable preposition.
I would like to have a new watch ________ my birthday.
The sentence needs to be filled with a preposition of reason, so ‘for’ is the apt answer. The speaker needs a new watch because it is his or her birthday. Thus birthday is the reason, hence option C is correct. The preposition ‘to’, ‘with’ and ‘of’ are unsuitable in the given context. If we use ‘to’ it would mean that 'my birthday' is a person to whom the gift is given, because ‘to’ is used to denote the receiving end. ‘With’ is used to denote a tool or company, whereas ‘birthday’ is neither of these. 'Of’ is used to denote belonging which is once again not the case. Therefore options A, B and D are incorrect.