The correct answer is B - Numbers get smaller as you move to the left on the number line.
This is true because as you move farther to the left, the numbers become smaller and eventually move into the negatives.
A is incorrect because no number line has a distinct ending. C also is incorrect because the numbers do not get larger as you move in the direction of the "smaller" numbers. Lastly, D is an incorrect option because number lines are often used to compare numerals.