The correct answer is (b). Maternal mortality rate is a key indicator of the health of a population. It is the number of women who die from pregnancy-related causes per 100,000 live births. A high maternal mortality rate indicates that women are not receiving the quality of healthcare they need, and that there are underlying health problems in the population.
Infant mortality rate is the number of deaths of infants under one year of age per 1,000 live births. It is another important indicator of the health of a population. A high infant mortality rate indicates that there are problems with access to healthcare, nutrition, and sanitation.
Access to clean water is a basic human right and essential for good health. People who do not have access to clean water are at risk of contracting waterborne diseases such as cholera, typhoid, and diarrhea.
Prevalence of diseases is the number of people in a population who have a particular disease. It is an important indicator of the health of a population, but it does not necessarily reflect the quality of healthcare that is available.
In conclusion, the correct answer is (b). Maternal mortality rate is the best indicator of the health of a population.