Choose the correct Preposition that should be inserted in the blank : -

"The school was not far from my home and I used to walk, but _______ the start of last year I had been going with the other girls in a rickshaw and coming home by bus".

since

The correct preposition to fill the blank is: since

Here's why:

• The sentence describes a change in routine that happened at a specific point in the past ("the start of last year").
• "Since" is used to indicate the beginning of a period of time that continues up to the present or a specified point in the past.