Find the equation of a circle whose diameter has ends points (4, 3) and (-2,1).

$x^2+y^2 - 2x - 4y = 3$ $x^2+y^2 - 2x - 4y = 5$ $x^2+y^2 - 6x + 2y = 3$ $x^2+y^2 - 2x + 4y = 5$

$x^2+y^2 - 2x - 4y = 5$