A circular loop of radius $R$, carrying a current $i$ lies in the $x-y$ plane with its centre at the origin. The total magnetic flux through the $x-y$ plane is

Question

$\begin {array} {1 1} (a)\;Directly\: proportional \: to\: R & \quad (b)\;Directly\: proportional \: to\: i \\ (c)\; Inversely proportional to R & \quad (d)\;Zero \end {array}$