Fill in the blank with a suitable preposition.
She will start working for our company _______ September.
The preposition ‘from’ is used to refer to the beginning of an action or event, while ‘to’ is used to refer to the end of a period. In the given context the person starts her work starting from September; therefore, option B is correct while option D is incorrect. Whereas preposition ‘on’ is used to denote a day/date or a place which is not the case here so option A is incorrect. Similarly ‘for’ is used to either denote a reason or to speak about an entire period. Since the sentence is speaking about the beginning of a new job and not a whole period, option C is incorrect.