Biot-Savart Law & Circular Coils question from JEE Main 2013 (22 Apr, Shift 1)

Answer: (a)

1. The loop cuts the page at two points: current out of the page ($\odot$) on the left, into the page ($\otimes$) on the right.
2. Out-of-page current: field lines anticlockwise, so just to its right the field points up. Into-page current: clockwise, so just to its left the field also points up.
3. Between the two points the fields add (pointing up), the central line is straight along the axis and lines curve around each wire.
4. So the answer is (a).