Final answer:
The nurse's priority is to assess immediate medical needs.
Step-by-step explanation:
The nurse's priority in caring for a client who has become homeless following a recent tornado is to assess immediate medical needs (option b). While providing emotional support (option a) is important, ensuring the client's medical needs are addressed takes precedence. Arranging temporary housing (option c) and providing food and water (option d) are also important, but assessing and addressing any immediate medical needs is the nurse's top priority.