Really, none of these answers are good. leukocytes are the body's general immune cell, and lymphocytes are a type of leukocyte. Antibodies are only used when fighting an infection that your body already has experience with, so I'm guessing it you have to pick from these answers, its "lymphocytes", but it's not really the best answer.
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.
