Answer:
B.
Explanation:
The distance between two any points a i b is |a-b| as we don't know which of them is larger number.
So:
a=-2 and b=1 means distance |-2-1| = |-3| = 3
{If we know the value of given points we can subtract the smaller one from the larger. It also works: -2<1, so the distance would be 2-(-1)=2+1=3}