Final answer:
Nurses should be aware of the diagnosis and symptoms of preterm labor.
Step-by-step explanation:
Nurses should be aware that the diagnosis of preterm labor is based on gestational age, uterine activity, and progressive cervical change (option d). In preterm labor, the cervix starts to dilate and efface, leading to regular contractions that become more frequent and powerful with time (option a). Braxton Hicks contractions, on the other hand, are weak and irregular contractions that do not abate with rest or hydration and can often be relieved with rest or hydration (option b).