The train has parted A. ——0——0 B. 0___0 C. _____00 D. 00___

The correct answer is A. ——0——0.

The other options are incorrect because they do not represent the correct number of cars in the train. Option B has 5 cars, option C has 3 cars, and option D has 2 cars. The correct answer, option A, has 4 cars.

The train has parted, which means that it has left the station. The cars are evenly spaced, with one car between each pair of dots. The first car is at the front of the train, and the last car is at the back of the train.