if given arrangement is moving towards left with speed v then potential difference between b and d and current in loop are respectively
Answer is (4) plz tell the reason

EMF= BVL where L = distance between point B and D= 4R
        = 4BVR
positive end of the loop is given by unit vector of vxB. that is point D and corresponding B point is negative
and therefore current flows from D to B. hence option 3 is correct.