Magnetic field induction at athe cetre O of a square loop of side a carrying current I as shown in figure is

Options

A. `- (dvecB)/(dt)pir^2` in loop 1 and zero in loop 2
B. `- (dvecB)/(dt)pi R^2` in loop 1 and zero in loop 2
C. Zero in loop 1 and zero in loop 2
D. `- (dvecB)/(dt)pir^2` in loop 1 and `(dvecB)/(dt)pir^2` in loop 2