Final answer:
Visual disturbances in a pregnant teenager could signal danger and may be a symptom of preeclampsia, a condition characterized by high blood pressure and organ damage.
Step-by-step explanation:
Of all the complaints mentioned, visual disturbances in a pregnant teenager could signal danger. Visual disturbances during pregnancy may be a symptom of a condition called preeclampsia, which is characterized by high blood pressure and damage to organs such as the liver and kidneys. It is important for pregnant teenagers experiencing visual disturbances to seek immediate medical attention to rule out preeclampsia and ensure the health and safety of both the mother and baby.