In an elastic collision, an object with momentum 25 kg⋅m/s collides with another that has a momentum 35 kg⋅m/s. The first object’s momentum changes to 15 kg⋅m/s. What is the momentum of the second object after the collision?

a. 5 kg⋅m/s

b. 10 kg⋅m/s

c. 25 kg⋅m/s

d. 75 kg⋅m/s