The correct answer is: a) Floods.
Early warning systems are crucial for timely evacuation during floods because they can provide people with the time they need to get to safety. Floods can cause extensive damage to property and infrastructure, and can even be deadly. Early warning systems can help to reduce the loss of life and property by giving people time to evacuate before the floodwaters arrive.
Earthquakes are another natural disaster that can cause significant damage and loss of life. However, early warning systems are not as effective for earthquakes as they are for floods. This is because earthquakes can occur very suddenly, with little or no warning. As a result, it is often difficult to evacuate people before the earthquake strikes.
Landslides are also a natural hazard that can cause significant damage and loss of life. However, early warning systems are not as effective for landslides as they are for floods or earthquakes. This is because landslides are often caused by a combination of factors, including rainfall, soil erosion, and human activity. As a result, it is often difficult to predict when a landslide will occur.
Droughts are a natural hazard that can cause significant damage to agriculture and ecosystems. However, early warning systems are not as effective for droughts as they are for floods, earthquakes, or landslides. This is because droughts are often slow-moving events that can develop over a period of months or even years. As a result, it is often difficult to predict when a drought will occur and how severe it will be.
In conclusion, early warning systems are most effective for natural disasters that can be predicted with some degree of accuracy, such as floods. They are less effective for natural disasters that are more difficult to predict, such as earthquakes and landslides.