Answer:
The most vulnerable is A. The less vulnerable is B.
Explanation:
Based on diagram A, a pregnant woman and a child are Walking away from the rolling boulder. Children and Pregnant women are less athletic than a normal person. This puts them on a higher risk of being crushed.
While B on the other hand, has full-grown adults who are actively running away from the falling boulder. Running is far more effective than walking in terms of dodging a speeding boulder. And since they are fully grown and not pregnant they place no burden on their agility. Hence, they are less vulnerable.
