A nurse is teaching the client about common discomforts in the first trimester of pregnancy as well as warning signs of potential danger. The nurse should instruct the client to call the clinic if she experiences which of the following manifestations?

A. Increased urination, especially at night: Frequent urination is a common and expected symptom in early pregnancy due to hormonal changes and increased pelvic blood flow. It does not typically signal a complication unless accompanied by other concerning signs like burning or fever. B. Occasional mild headaches relieved with rest: Mild headaches can occur in early pregnancy due to hormonal shifts or fatigue. As long as they are infrequent and relieved by rest or hydration, they are considered a normal discomfort rather than a warning sign. C. Breast tenderness and enlargement: Hormonal changes in early pregnancy often cause breast sensitivity and fullness. This is a common physical change and generally not a cause for concern unless accompanied by signs of infection or abnormal discharge. D. Persistent vomiting that prevents fluid intake: Excessive vomiting, especially if it leads to dehydration or inability to tolerate fluids, may indicate hyperemesis gravidarum. This condition can require medical treatment and poses risks to both maternal and fetal health if untreated.