Please answer the above question of magnetism quickly. I m not getting the right answer.

Ans is option 2. Force per unit length is given by :- F` = uIi/2πd.Where I and i are currents carried by wires and d id the distance between them. Also the force is attractive if wires carry current in same direction but repulsive if currents has opposite direction. Apply this formula and you will get the answer. Driving this formula is also easy. Assume B at distance d because of one wire and take some length of the second wire and write force, to cancel out the length name it “force per unit length”.