This question checks the meaning of the phrase "call it a day", which people use when they decide to stop an activity for the time being, usually because enough work has already been done.
The correct option is "Stop work", because the sentence is suggesting that, since it is late and much has already been achieved, it makes sense to end the work for the day.
Let's summarize:
So the option that best expresses the meaning of "call it a day" is "Stop work".
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?