The Correct option is **C) M**_{1} = M_{2}

**Explanation:**

Kinetic energy of M_{1} before collision

Kinetic energy of M_{1} after collision

Kinetic energy transferred from M1 to M2, ΔK = decrease in kinetic energy in projectile

So, Remember,

Transfer of energy will be maximum if the difference between the masses is minimum.

If M1 = M2

So, if M1 and M2 are equal then there will be maximum possible transfer of energy.