Which of the following statement(s) is/are true?

1. Inadequate infrastructure does not have multiple adverse effect on the health.
2. Improvement in sanitation has a large impact by reducing morbidity from major waterborne diseases.
3. Improvement in water supply does not reduce the severity of disease.
4. Air pollution and safety hazards connected to transportation also affect morbidity.

B and D only

The correct answer is option 4: B and D only

Let's analyze each statement:

1. Inadequate infrastructure does not have multiple adverse effects on health: False. Inadequate infrastructure can lead to various health issues, including increased morbidity and mortality rates.

2. Improvement in sanitation has a large impact by reducing morbidity from major waterborne diseases: True. Improved sanitation is crucial for reducing the incidence of waterborne diseases.

3. Improvement in water supply does not reduce the severity of disease: False. Improving water supply typically reduces the severity of diseases related to poor water quality and sanitation.

4. Air pollution and safety hazards connected to transportation also affect morbidity: True. Air pollution and transportation safety hazards are significant factors that can increase morbidity rates.