Answer:
A is the correct option.
Explanation:
Let us suppose that it will take x days to produce 200 liters.
Now, it has been given that the farm produces an average of 17.1 liters of milk per day.
Hence, in x days the farm will produce 17.1x liters of milk. This should be equal to the given amount of milk which is 200 liters. Hence, we have

Divide both sides by 17.1, we get

Hence, it will take about 12 days to produce 200 liters of milk.
A is the correct option.