Investor pessimism: is the world outlook getting worse?

THE queue was ten-children long, when the first one in line passed out, causing some commotion. The second child went through without any problems. The third, who was standing right in front of me, also proceeded to faint, causing an increasing sense of dread in the rest of the line. In a show of solidarity, I joined the first two children, dropping on the ground. We had all just received our vaccine jab at the local school in Italy. The nurse assured our parents that episodes like this were common with impressionable young children, and there was nothing to worry about.

Vaccination days have been held throughout developed countries for decades. Here's a question: With the birth rate in developed countries dropping below the replacement rate, while poorer countries continue to have a higher number of births, how many of the world's one-year old children today have been vaccinated against some disease?

A: 20% B: 50% C: 80%