Final answer:
The correct nursing diagnosis for the patient is activity intolerance related to fatigue.
Step-by-step explanation:
The correct nursing diagnosis for the patient described would be activity intolerance related to fatigue.
The patient's symptoms of ankle edema, weight gain, and feeling too tired to get out of bed indicate that they are experiencing difficulty in performing physical activities due to fatigue. Activity intolerance refers to the reduced ability to perform necessary activities of daily living or engage in physical activities due to insufficient energy or endurance.
In this case, the patient's chronic heart failure may be causing inadequate cardiac output and oxygen supply to the muscles, leading to fatigue and difficulty with physical exertion.