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:

* Smokers seeking treatment
* Aged 18 and over
* Consenting to take part in the trial

Exclusion Criteria:

* Pregnant or breastfeeding
* End-stage renal disease
* Unable to fill in questionnaires in English
* Previous allergy to Varenicline
* Previous allergy to Nicotine Patches Previous allergy to varenicline
C: Inclusion Criteria:

* The sample, 40 women and 40 men, will be hospitalized patients recruited from Stanford Hospital and Clinics who report smoking at least 10 cigarettes per day prior to hospitalization, have confirmed tobacco use by cotinine testing, and an expected hospitalization of at least 3 days duration from the date of study enrollment. Intention to quit smoking will not be required for study participation.

Exclusion Criteria:

- Study exclusion criteria are: dementia or other brain injury precluding ability to participate; Alzheimer's Disease; Parkinson's Disease; Huntington's Disease; meningitis; seizure disorder of a sustained nature; delirium; brain surgery; drug and/or alcohol dependence; suicidal ideation; end-stage renal disease (i.e., on dialysis); hypertensive crisis; stroke; myocardial infarction (MI) with severe cardiac damage; pregnancy or breastfeeding; non-English speaking; complete homelessness; or currently engaged in tobacco treatment. Study staff will consult with clinical staff prior to approach for study enrollment. In cases of severe renal impairment (estimated creatinine clearance \<30 mL/min), medical staff will consult with participants' physician to assess the appropriateness for study enrollment.
D: Inclusion Criteria:

A software program using Anatomical Therapeutical Chemical (ATC) prescription codes and International Classification of Primary Care (ICPC) diagnosis codes selected potential patients with COPD. Criteria: age \>35 years and a diagnosis recorded as COPD or as ICPC code R95/96, or a prescription of at least three times of bronchodilators (ATC code R03a/bc) and/or prescription of at least two times of inhaled anti-inflammatory medication in the past year (ATC code R03). General practitioners (GPs) had to confirm the diagnosis of the selection. Patients were eligible to participate if they met the following criteria:

* Current smoking
* Suffering from COPD according to the GP's diagnosis
* In command of the Dutch language.

Exclusion Criteria:

* Too ill
* Under control of a chest physician
* Serious physical or psychological comorbidity

Answer: A