Answer:
D, BC = 6 units.
Explanation:
Identify your two points B = -4, and C = 2.
To get the difference, you've got to either count them, or use an equation to find it.
Counting, you can see there is 1, 2, 3, 4, 5, 6 dots encompassed in the line BC.
To use an equation, you can do BC = 2 - (-4), in which negatives cancel out to equal a positive, and you still get 6 units total