The logo given is of

1. UNO
2. UNICEF
3. WHO
4. UNESCO

It makes a worldwide immunisation campaign to prevent the six major communicable diseases of children:

1. WHO
2. UNO
3. UNICEF
4. UNESCO

One of the main functions of this agency is to open libraries and remove illiteracy:

1. WHO
2. UNICEF
3. UNO
4. UNESCO

The largest sector of the UNESCO activity is related to

1. Culture
2. Education
3. Science
4. Communication