Geometry

The answer is C. 8.

 

1. Recall the Ruler Postulate:

The Ruler Postulate states that if two points  and  on a number line have coordinates  and  respectively, then the distance between them .

 

Here, for points  and  with coordinates  and , the distance between  and  is .

 

2. Substitute the values of  and  into the formula:

Substitute  and