What is NOT true about quitting tobacco use? Select one:

a.
If a former smoker takes a single puff, it can increase his or her odds of relapse greatly.

b.
After 15 to 20 years of quitting, coronary heart disease returns to the same risk as nonsmokers.

c.
Even a month or so after quitting, lung function improves.

d.
It can take many attempts before finally breaking the habit.

e.
It's easy once you decide to quit.