Please select the eligibility criteria that correspond to the clinical trial below.
Title: Varenicline for Long-term Nicotine Replacement Therapy (NRT) Users. A Double Blind, Placebo Controlled Trial
Brief Summary: Primary aim: Will varenicline be better than placebo to get long-term users of NRT to stop?

Secondary aim: To assess in details some side effects of varenicline i.e. nausea and abnormal dreams.


Options:
A: Inclusion Criteria:

* Long-term, daily NRT users (except nicotine patch) (\>11 months) ex-smokers that are willing to try to stop the use of NRT and adhere to this protocol.
* More than 4 pieces of nicotine gum/ sublingual tablets/ lozenges/ per day, OR more than 3 inhaler cylinders per day, OR
* more than 10 puffs of nasal spray per day.

Exclusion Criteria:

* Age \< 18 years,
* CO Smokers,
* Pregnant and lactating women,
* Used varenicline before,
* Not able to cooperate,
* Other significant diseases that might influence the trial (such as moderate -severe cardiac disease, lung cancer,) in expired air \> 7 ppm.
B: Inclusion Criteria:

1. Subject is at least 18 years of age;
2. Subject has provide written informed consent;
3. Subject is smoking greater than or equal to 10 cigarettes per day for at least 6 months;

3) Subject is able to complete all study visits 4) Subject is in good health as determined by the investigator 5) Subject has the ability to participate fully in all aspects of the study and keep scheduled appointments 6) Subject is motivated to stop smoking.

Exclusion Criteria:

Female and were pregnant, lactating or likely to become pregnant during the trial and not able nor willing to use contraception or had:

1. an unstable medical condition;
2. another household member participating in the study;
3. bupropion or varenicline allergy;
4. current use (previous 30 days) of a tobacco dependence treatment and unable or unwilling to discontinue use;
5. an unstable medical condition or unstable angina, myocardial infarction, or coronary angioplasty (past 3 months) or an untreated cardiac dysrhythmia;
6. a history of renal failure or were on renal dialysis;
7. a history of seizures;
8. as defined by the C-SSRS (Columbia-Suicide Severity Rating Scale), current non-specific suicidal thoughts or lifetime history of a suicidal attempt (defined as "potentially self-injurious act committed with at least some wish to die, as a result of act");
9. a history of closed head trauma associated with \> 30 minutes of loss of consciousness, amnesia, skull fracture, subdural hematoma, or brain contusion;
10. a history or psychosis, bipolar disorder, bulimia or anorexia nervosa;
11. current moderate or severe depression as assessed by a score of ≥ 20 on the Beck Depression Inventory, Second Edition (BDI-II) 10;
12. active substance abuse other than nicotine;
13. current (past 14 days) use of an antipsychotic, monoamine oxidase inhibitors, or drugs known to interact with bupropion SR;
14. a recent dose change of their antidepressant (within last 3 months);
15. untreated hypertension or baseline systolic blood pressure \> 180 or diastolic \> 100;
16. current treatment with another investigational drug for tobacco dependence (previous 30 days); or
17. current use of bupropion or varenicline (previous 30 days).
C: Inclusion Criteria:

* Subjects must have smoked an average of at least 10 cigarettes per day during the past year and over the month prior to the screening visit, with no period of abstinence greater than 3 months in the past year.

Exclusion Criteria:

* Subjects with clinically significant cardiovascular disease in the past 6 months.
D: Inclusion Criteria:

* ≥ 18 years of age
* Smoke at least 10 cigarettes/day for the past year
* Suffered an enzyme-positive ACS
* Planned hospitalization of ≥24 hours
* Motivated to quit smoking
* Likely to be available for follow-up
* Able to understand and read English or French

Exclusion Criteria:

* Medical condition with a prognosis of \< 1 year
* Pregnant or lactating
* Current use of Wellbutrin or any other medications that contain bupropion
* Current use of any medical therapy for smoking cessation (e.g. BuSpar, fluoxetine, doxepin, nicotine gum, or nicotine patch)
* Current seizure disorder, history of seizures or predisposition to seizures (e.g. history of brain tumor, severe head trauma, or stroke)
* History of bulimia or anorexia nervosa
* Current diagnosis of major depression (requiring medication), bipolar disease, or dementia
* History of suicidal events (previous suicide attempt, suicidal ideation) or family history of suicide
* Diagnosed hepatic failure, cirrhosis, hepatitis or history of hepatic impairment (AST or ALT levels ≥ 2 times upper limit of normal prior to admission for ACS)
* Renal impairment with creatinine levels ≥ 2 times the upper limit of normal
* Excessive alcohol consumption defined as ≥ 14 alcoholic drinks per week
* Use of any illegal drugs in the past year (e.g. cocaine, heroin, opiates)
* Current use of medications that lower seizure threshold e.g. amantadine, anti-depressants, anti-malarials, anti-psychotics, levodopa, lithium, quinolone antibiotics, ritonavir, systemic steroids, theophyllin, type 1C antiarrhythmics (e.g. encainide, flecainide, propafenone)
* Use of MAO inhibitors or thioridazine in the past 15 days
* Current use of over-the-counter stimulants (e.g. ephedrine, phenylephrine) or anoretics

Answer: A