Answer:
C. More young children live in Country 1 than in the other countries.
Step-by-step explanation:
The described graph shows that more young children live in Country 1 than in the other countries. This is clearly stated in the first paragraph: This is the greatest percentage of any 4-year age span in all three countries. This automatically means that options B and D are incorrect.
Option A is the second-best one. However, the fact that there are more young children in Country 1 doesn't necessarily mean that their death rate is lower. It could be, but correlation doesn't equal causation. There are more young children probably because the younger population is more present in that country and more children are born.
This is why option C is the correct one.