Final answer:
The distance between 0 and -2 on a number line is the absolute value of the difference, which is 2 units. Thus, the correct answer is option B.
Step-by-step explanation:
The distance between two numbers on a number line is the absolute value of the difference between those numbers. So, to find the distance between 0 and -2, we calculate the absolute value of the difference between these two points, which is |0 - (-2)| = |2| = 2. Therefore, the distance is 2 units on the number line, making option B the correct answer.