Final answer:
Non-phosphate detergents should be used for cleaning boats because they are environmentally friendly and do not promote eutrophication, which can deplete oxygen levels in water and harm aquatic life.
Step-by-step explanation:
When cleaning a boat, only non-phosphate detergents should be used because they are environmentally friendly (Option B). Phosphates are known to cause environmental issues by promoting eutrophication. This refers to the excessive growth of algae in water bodies which can lead to a significant decrease in dissolved oxygen. The reduction in oxygen can be harmful to aquatic life, including fish, leading to potential die-offs and negatively affecting the ecosystem. Many regions, including several states in the United States and countries like France, have banned or restricted the use of phosphate-containing detergents due to these environmental concerns. Moreover, phosphate-free detergents usually contain alternative complexing agents, like derivatives of acetic acid or other carboxylic acids, that do not have the same detrimental environmental impacts.