Write an equation in standard form for the given circle

The generic equation of the circle is:
 (x-xo) ^ 2 + (y-yo) ^ 2 = r ^ 2
 The first thing we must see for this case is where the circle is centered.
 We note that the circle is centered on the following ordered pair:
 (xo, yo) = (-1, -3).
 We now observe the radius of the circle:
 The diameter is:
 d = l-5 - (- 1) l
 d = 4
 the radio will be:
 r = d / 2 = 4/2 = 2
 r = 2
 Substituting values:
 (x - (- 1)) ^ 2 + (y - (- 3)) ^ 2 = (2) ^ 2
 Rewriting:
 (x + 1) ^ 2 + (y + 3) ^ 2 = 4
 
 The equation of the circle is:
 (x + 1) ^ 2 + (y + 3) ^ 2 = 4
 option 3