Final answer:
The statement that requires intervention by the nurse is the one suggesting that the lotion takes longer to work when applying lindane (Kwell).
Step-by-step explanation:
The nurse evaluates the client's understanding of the procedure for application of lindane (Kwell). Out of the given statements, the one that requires intervention by the nurse is option c, which states that 'The lotion takes longer to work.' This statement is incorrect because lindane (Kwell) is available in three forms: cream, lotion, and shampoo, and the time required for it to work is not dependent on the form used. The nurse should correct this misinformation and explain that the application time remains consistent across all forms.