Students in your class are continuing to model the motion of Triton $($one of Neptune's $13$ moons$)$ around Neptune, but now using VPython. The code your class has received contains the following snippet of VPython code.

from visual import $*$

Neptune $=$ Spheretpos$-$vector $(100,200,300),$ radius$=1,$ color$=$color.blue$)$

Triton $=$ sphere $($pos$=$vector $(10,20,30),$ radius$=2,$ color$=$color. white$)$

$($a$)$ From this snippet, which of the following lines of code might your group write to describe the separation vector pointing from Neptune to Triton in Vyython?

rvec$-$Triton, pos$-$Neptune, pos

rvec$=$Neptune. pos$-$Triton, pos

$($b$)$ Several groups have written a different lines of code to calculate the magnitude of the separation vector; some are correct and some are incorrect. From your understanding of the line$($s$)$ of code below, which of them correctly represent the magnitude of the separation vector between Neptune and Triton?

Select all that are True.

rmag$=$mag $($Neptune$.$pos$)-$mag $($Triton$.$pos$)$

rmag$=$mag $($Triton$.$pos$)-$mag $($Neptune$.$pos$)$

rmag$=$mag $($Neptune$,$ pos$-$Triton. pos$)$

rmag$=$mag $($Triton$,$ pos$-$Neptune, pos$)$