Final answer:
The most appropriate nursing intervention would be to allow the mother to stay with the child at all times to alleviate their fears and anxiety.
Step-by-step explanation:
The most appropriate nursing intervention to alleviate the child's fears and the mother's anxiety would be to allow the mother to stay with the child at all times (option b).
By allowing the mother to stay with the child, it provides a sense of security and comfort for both the child and the mother. Being hospitalized can be a stressful experience for a child, especially at a young age, and having the mother present can help reduce anxiety and promote emotional well-being.
Furthermore, research has shown that parental presence during hospitalization can have numerous benefits, including increased satisfaction, improved cooperation with medical procedures, and decreased feelings of fear and anxiety.