Final answer:
High-quality day care is an example of primary prevention of child maltreatment, as it provides a safe and supportive environment for children, which in turn can reduce the risk of maltreatment.
Step-by-step explanation:
One example of primary prevention of child maltreatment is B. high-quality day care. Primary prevention strategies focus on preventing maltreatment before it can occur, through measures such as providing safe environments, education, and support for families. High-quality day care offers a protective environment for children while also providing support to families, potentially reducing the risk of maltreatment.
Measures like emergency medical treatments are not primary prevention strategies, as they are responses after an incident has occurred. Similarly, parental education can be considered a preventive measure, but it is more educational in nature and does not provide a direct, immediate protective environment like day care does.