How does direct application contribute to the contamination of water bodies?

Direct application refers to the application of pesticides, herbicides, or fertilizers in a manner that allows them to enter the environment more quickly. When these substances are directly applied to the ground, especially in areas close to water bodies, they can easily be washed away by rain or irrigation. This process is known as runoff.

The correct choice highlights that direct application can lead to immediate runoff into water sources. This is a significant concern because it means that harmful chemicals can enter rivers, lakes, and streams almost as soon as they are applied. Such contamination can have severe effects on aquatic ecosystems, wildlife, and even human health, leading to issues like toxic algal blooms or the presence of harmful chemicals in drinking water.

On the other hand, while the other options suggest various scenarios, they do not accurately capture the immediate and direct danger posed by runoff from direct applications. For example, stating that it does not contribute significantly overlooks the real risks associated with contaminants reaching water bodies. Discussing application at the wrong temperature or only affecting surface-level water bodies does not address the broader and immediate concern of runoff, which can encompass various water bodies, including deeper or more remote sources.