Which of the following choices is the most important to do before starting an exercise program?
a. see your doctor
b. talk to your friends for advice
c. lift some weights
d. measure your body fat
select the best answer from the choices provided.

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases.