Kiran's statement:Change in momentum of the insect and the motorcar is equal by conservation of momentum. The velocity of the insect changes significantly because its mass is very small compared to the motorcar. Similarly, the velocity of the motorcar is very insignificant because its mass is very large compared to the insect. Hence, Kiran's statement is false.
Akhtar's statement:By Newton's third law of motion, action and reaction forces are equal and opposite and they act on different bodies. Hence, the motorcar and insect both experience the same force. Since the mass of the insect is very small compared to the motorcar, it suffers a huge change of velocity as compared to the car. Due to this, the insect dies. Hence, Akhtar's statement is false.
Rahul's Statement:As discussed before, both the motorcar and the insect experience the same force and change in momentum. Hence, Rahul's statement is correct.