Answer & Solution
Option A: 250 ml
250 ml is incorrect as it is much smaller than a quart.
Option B: 500 ml
500 ml is half of a liter and also less than a quart.
Option C: 750 ml
750 ml is still less than a quart and is commonly used as a standard bottle size for wine.
Option D: 1000 ml
1000 ml is equivalent to 1 liter, which is very close to the volume of one quart (1 US quart ≈ 946 ml, 1 UK quart ≈ 1136 ml). Thus, 1000 ml is generally accepted as equivalent to one quart in practical terms.
Conclusion:
One quart is approximately equal to 1000 ml, making Option D the correct answer.