The correct answer to the question is : B) The big ball transfers some of its momentum to the small ball but it keeps going forward too.
EXPLANATION :
Before going to answer this question, first we have to understand the law of conservation of momentum.
As per law of conservation of momentum, the momentum of an isolated system is always constant. Hence, the momentum is always conserved both in elastic as well as in inelastic collision.
As per the question, the big rolling ball hits the smaller rolling ball.
Due to this collision, the big rolling ball will give some of its momentum to the small rolling ball. But, the big ball will move along its initial direction as small ball can not affect its direction of motion.
Hence, the correct answer of this question is option B.