if you draw an auxillary line from (-1,4) to (-1,-2) we see we get 2 right triangles
so we have one leg is 2 units
the auxilary line from (-1,4) to (-1,2) is 6 units that is another leg
and the hyptonuse is the missing side
so
a²+b²=c²
a=6
b=2
c=c
6²+2²=c²
36+4=c²
40=c²
sqrt both sides
2√10=c
the other side is idenical so the perimiter is bottom+2 times side
p=4+2 times 2√10=4+4√10≈16.6491106
answer is D