Respuesta :

 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