Final answer:
In this situation, the priority nursing action should be to reduce the client's anxiety level.
Step-by-step explanation:
In this situation, the priority nursing action should be to reduce the client's anxiety level. While medical treatment and evidence collection for the police are important, the client's emotional well-being should be addressed first. This can be done by providing emotional support, validating the client's feelings, and offering appropriate coping strategies.
Once the client's anxiety level is reduced, the nurse can then proceed with assisting with medical treatment and collecting evidence for the police, as needed.
Providing anticipatory guidance about normal responses to sexual assault is also important, but it is not the priority in this situation.