<em>The correct option is D) They soak up excess water that can potentially lead to flooding.</em>
Explanation:
A rain garden can be described as a depressed area in a landscape which comprises of plants like native shrubs and flowers. The primary purpose of building a rain garden is to hold and soak in rainwater. This causes to prevent a situation such as a flood because most of the excess water is trapped by the plants. Hence, situations such as erosion and flooding can be decreased by rain gardens.
Radiotherapy to relieve symptoms is also known as palliative radiotherapy. Palliative radiotherapy aims to shrink cancer, slow down its growth or control symptoms. It doesn't aim to cure cancer.
