Although emphysema is a serious condition which may be associated with smoking, it is quite clear from the history that this man did not die from it.
Emphysema is a condition in which the alveoli of the lungs are enlarged, reducing the surface area available for oxygen exchange. This was picked up at autopsy for this man. In severe cases there may be breathlessness and dependence on oxygen. In his case, the emphysema was not severe.
Re-read the history if you need to and try again.