If we consider it as a combination problem, then we could calculate the how many combinations are there if we pick up three nodes out of six nodes, and then we have:

And the answer should be 20
The standard equation of a circle:

We have the center (-4, 0) → h = -4 and k = 0, and the radius r= 3. Substitute:

I think it might be c or A
Answer:
1 and 5/24 gallon left
Step-by-step explanation:
https://www.slader.com/discussion/question/mark-wants-to-paint-a-mural-he-has-113-gallons-of-yellow-paint-114-gallons-of-green-paint-and-78-g-2/
its a reliable link