Well, I'm way past the 15 min mark, but here's how to do the question.
With this, you will need to use the distance formula,
, on XY, YZ, and ZX.
XY: 
Firstly, solve inside the parentheses: 
Next, solve the exponents: 
Next, solve the addition, and XY's distance will be √29
(The process is the same with the other 2 sides, so I'll go through them real quickly)
YZ:

ZX:

Now that we got the 3 sides, we can add them up: 
In short, your answer is 14.8, or the second option.