To find distance between 2 points apply Pithagoras theorem
X^2 + Y^2 = R ^ 2 for a rectangular triangle
X represents the difference between coordinates x and x'
Y represents the difference between coordinates y and y'
now find this values ( x - x') and ( y - y')
they are. (-8 -4) and ( 1 -(-6))
looking a the picture the first two options corresponds to this numbers. BUT theres a difference between them,
in the first one theres a + sign
in the 2nd one theres a - sign
the true answer is first, because Pithagoras theorem have a + sign .