Choice A Reason:

Reduced blood pressure is not a specific complication of infective endocarditis. While hypotension can occur in severe cases due to septic shock, it is not a hallmark of the disease. Infective endocarditis primarily affects the heart valves and can lead to embolic events, heart failure, and other complications.

Choice B Reason:

Osler's nodes are a classic sign of infective endocarditis. These are painful, red or purple, raised lesions found on the hands and feet. They are caused by immune complex deposition and are indicative of the systemic nature of the infection. Their presence can help in the clinical diagnosis of infective endocarditis.

Choice C Reason:

Clear lung sounds are not a complication of infective endocarditis. In fact, clear lung sounds would generally indicate that there is no pulmonary involvement or congestion. Complications of infective endocarditis are more likely to involve the heart, kidneys, and other organs through embolic events.

Choice D Reason:

Increased appetite is not associated with infective endocarditis. Patients with this condition often experience symptoms such as fever, fatigue, and weight loss due to the chronic infection. Increased appetite would be an unusual finding and not related to the disease process.