Multiple choice question. !

a man with heart disease lives in a family that eats a lot of red meat. what would a physician have to do to determine if the man's heart disease is entirely related to his environment?

analyze the patient's family history regarding heart disease
analyze the patient's diet to quantify cholesterol intake
determine the exact amount of cholesterol in the patient's blood
determine if the cholesterol will lead to high blood pressure

i think its the first one, but i'm not sure.