According to the Human Development Report 2016 of the United Nations Development Programme, how many people in developing countries have no access to safe water?

663 million

The correct answer is Option 4- 663 million

According to the Human Development Report 2016 of the United Nations Development Programme, 663 million people in developing countries have no access to safe water and 2.4 billion have no access to sanitation, resulting in the death of more than three million children every year.