about
on
of
in
Answer is Wrong!
Answer is Right!
The correct answer is (C).
The preposition “of” is used to indicate a part or portion of something. In this case, the fall is a part of the prices.
The preposition “about” is used to indicate a general idea or topic. In this case, the fall is not a general idea about prices, but a specific event that has happened to prices.
The preposition “on” is used to indicate a location or position. In this case, the fall is not a location or position, but an event that has happened to prices.
The preposition “in” is used to indicate a period of time. In this case, the fall is not a period of time, but an event that has happened to prices.