Please select the eligibility criteria that correspond to the clinical trial below.
Title: An Examination of the Efficacy, Safety, and Gender Differences in Using Varenicline as an Aid to Smoking Cessation in a Population of Methadone Maintained Opioid Dependent Patients (Pilot Trial)
Brief Summary: The main hypotheses guiding the study are:

1. Stable methadone maintenance patients receiving varenicline will be more likely to maintain abstinence than patients receiving placebo
2. There will be no differences in the type and number of symptoms reported between stable methadone maintenance patients receiving varenicline and placebo
3. There will be no changes in methadone dosage between abstinent and non-abstinent smokers
4. There will be no differences in efficacy, withdrawal symptoms, and safety of varenicline between male and female participants


Options:
A: Inclusion Criteria:

* Stable on methadone maintenance (an individual is considered 'stable' if they have had a 4 week constant/fixed dose of methadone by self report and verified by B.C. Pharmanet review)
* Subjects must have smoked 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
* Ages 19 to 75 years (inclusive) and motivated to quit smoking
* Should read and understand English
* For female subjects:

  * instructed and agrees to avoid pregnancy through 30 days after the last dose of study medication
  * has a negative urine pregnancy test at screening
  * agrees to use birth control method(s) for duration of the study
* Should be available by telephone

Exclusion Criteria:

* Subjects who have used varenicline previously or are currently on other Nicotine Replacement Therapy or pharmacotherapy for smoking cessation (e.g., nicotine patch, zyban or wellbutrin)
* Subjects who have a prior or current history of depression, bipolar affective disorder or a prior or current history of psychotic episodes or suicidal ideation (on the basis of self-report augmented by medical chart review where appropriate and/or corroborating history with previous or current health care provider)
* Subjects who have not reached a stable dose of methadone in their methadone maintenance therapy (4 weeks at a constant/fixed dose of methadone by self-report and verified by B.C. Pharmanet review)
* Pregnancy or currently nursing
B: Inclusion Criteria:

* Current male or female cigarette smokers who are motivated to stop smoking.
* Smoked an average of 10 cigarettes per day during past year and the month prior to first visit.

Exclusion Criteria:

* Patients who have used a nicotine replacement product, bupropion, clonidine or notriptyline within the past 6 months.
* Patients currently with depression or diagnosed with depression in past 12 months.
* Past or present history of psychosis, panic disorder, or bipolar disorder.
C: Inclusion Criteria:

* Cigarette smokers who are motivated to stop smoking and have smoked an average of at least 10 cigarettes per day

Exclusion Criteria:

* Subjects who have used a nicotine replacement product within 30 days of the study screening visit or intend to use it during the study.
D: Inclusion Criteria:

* smoking an average of at least 10 manufactured combustible cigarettes per day for at least 12 months prior to Screening
* tested positive for urine cotinine (≥ 200 ng/mL) at Screening
* exhaled carbon monoxide \> 10 ppm (parts per million) at Screening

Exclusion Criteria:

* relevant illness history
* relevant medication use
* body mass index (BMI) \> 40 kg/m2 or \< 18 kg/m2 at Screening
* allergy to propylene glycol or glycerin
* use of nicotine-containing products other than manufactured combustible cigarettes within 14 days prior to Check-in
* use of any prescription smoking cessation treatments within 3 months prior to Check-in
* smokers who draw smoke from the cigarette into the mouth and throat but do not inhale
* planning to quit smoking during the study
* female subjects who are pregnant, lactating, or intend to become pregnant

Answer: A