It is D, sharing appreciation for what is being said. Both A and B aren't crucial to being a good listener, in fact in practice they effectively draw attention to yourself, which would be fine if the question was regarding being a good conversationalist. Additionally, C is just completely irrelevant, that wouldn't even be a good conversation practice, let alone a trait important to listening.
Answer:
Smoking.
Being overweight or obese.
Lack of physical activity.
Too much salt in the diet.
Too much alcohol consumption (more than 1 to 2 drinks per day)
Stress.
Older age.
Genetics.
Cardiac output.
Peripheral vascular resistance.
Volume of circulating blood.
Viscosity of blood.
Elasticity of vessels walls.
Explanation: A lot of things acually.
