Final answer:
The nurse knows further teaching is necessary if the client believes that contractions will become less intense and more irregular.
Step-by-step explanation:
The nurse instructs a group of expectant clients on how to recognize the onset of labor. The nurse knows further teaching is necessary if the client makes the statement c) Contractions will become less intense and more irregular.
During the early stages of labor, contractions will typically start to become more frequent, regular, and intense, rather than less intense and irregular. As labor progresses, contractions will continue to increase in frequency and duration. Therefore, if a client believes that contractions will become less intense and more irregular, it indicates a need for further teaching.