Pls with this pre-calc question on

The answer is the option C, which is:

 C. √29

 The explanation of this exercise is:

 To solve this problem you must apply the proccedure shown below:

 1- You have that:

 W (-2,8,-3) and  X(1,4,-1)

 2- Therefore, you can calculate the magnitude as below:

 |WX|=√[(1-(-2)]²+(4-8)²+[(-1-(-3)]²)
 |WX|=√29