Correct Answer  Option 2 : decreases by 99 kgms
1
The correct answer is option 2) i.e. decreases by 99 kgms1
CONCEPT:

Momentum: Momentum is the impact due to a moving object of mass m and velocity v.
The momentum (p) of an object is expressed as:
⇒ p = mv
CALCULATION:
Initial speed of the body, u = 10 m/s
Final speed of the body, v = 10 cm/s = 0.1 m/s
Initial momentum, p_{1} = mu = 10 × 10 = 100 kgms^{1}
Final momentum, p2 = mv = 10 × 0.1 = 1 kgms1
Change in momentum = p_{2}  p_{1} = 1  100 = 99 kgms^{1}
Therefore, the momentum decreases by 99 kgms1