The answer for the problem shown in the figure attached is the option b, which is:
b: (7,11,1); 3√19
The explanation for the exercise is:
1- To solve this problem you must apply the proccedure shown below:
2- You have:
R(3,7,-1) and S(10,-4,0)
3- Then S-R is:
(7,-11,1)
4. And the magnitude is:
|RS|=√(7^2+(-11)^2+1^2
|RS|=3√19