Which is the safest and most effective way to get a deeper stretch? massage the muscles being stretched inhale and push the stretch until it hurts lean into the stretch as you exhale place ice on your muscles before stretching

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. 

The answer is d  vote brainliest if this ! : )