Final Answer:
The correct answer is option (d)
This discrepancy is explained by considering the relationship between mass, velocity, and kinetic energy in the context of the given scenario.
Step-by-step explanation:
In this scenario, the relationship between the masses ((m)) and kinetic energies ((K)) of particles A and B can be expressed as

Firstly, the mass of particle A is eight times that of particle
This implies that particle A is significantly more massive than particle B. Mass is directly proportional to kinetic energy for a given velocity, so particle A having a greater mass contributes to its higher kinetic energy.
Secondly, the kinetic energy of particle A is half that of particle
This suggests that despite being more massive, particle A has less kinetic energy. The relationship between kinetic energy and mass involves the square of the velocity
so a reduction in velocity or a smaller velocity distribution in particle A compared to B can explain the observed relationship.
In conclusion, the correct option is (d) because it accurately reflects the given conditions where particle A is eight times more massive than particle B, and yet its kinetic energy is only half of that of particle B.