Final answer:
The most appropriate response when a 40-week pregnant woman reports blood-tinged mucus is to instruct her to come to the clinic for an examination, as it may indicate that labor is imminent.
Step-by-step explanation:
When a woman who is 40 weeks pregnant reports a small amount of blood-tinged mucus, known as the "bloody show," it is often a sign that labor may start soon. This occurrence is due to the loosening and expulsion of the mucus plug that accumulated in the cervical canal during pregnancy, which can happen approximately 1-2 days prior to the onset of true labor. Hence, the most appropriate response by the nurse would be: "Come to the clinic today for an examination." This allows for professional assessment to determine if labor is imminent and if any further medical care or observation is necessary.