Final answer:
The patient with symptoms indicating cardiac distress should be placed in an upright position to assist with breathing and may also be given oxygen at 2 L/min via nasal cannula to increase oxygen saturation.
Step-by-step explanation:
The 67-year-old female patient with a history of congestive heart failure presenting with difficulty breathing and chest discomfort requires immediate treatment to alleviate her symptoms and stabilize her condition. Given her blood pressure is on the lower side and her heart rate is elevated, the best course of action is D) placing her in an upright position. This will help her breathe more easily. Nitroglycerin is usually indicated for chest pain, but given her low blood pressure, it might not be the safest choice without further medical assessment. Option C, providing oxygen at 2 L/min via nasal cannula, could also be a valid treatment to improve her oxygen saturation, especially in the context of her heart condition and the presence of dyspnea. Administration of supplemental oxygen is an essential immediate treatment for myocardial infarction (MI) to improve oxygen delivery to the myocardium, alongside medications such as aspirin and thrombolytics for longer-term management.