On a coordinate plane, triangle A B C is shown. Point A is at (negative 1, 6), point B is at (negative 1, 1), and point C is at (2, 2).
Triangle ABC is an isosceles triangle in which AB = AC. What is the perimeter of △ABC?

a
5 + StartRoot 10 EndRoot units
b
StartRoot 10 EndRoot units
c
10 + StartRoot 10 EndRoot units
d
15 units