Please select the eligibility criteria that correspond to the clinical trial below.
Title: Vascular Effects of Regular Cigarettes Versus electronIc Cigarette Use
Brief Summary: The purpose of this study is to assess the effects of electronic cigarettes-nicotine and electronic cigarette-nicotine free on endothelial function as compared to traditional cigarettes. Due to ethical reasons, we cannot fully randomise all particpants to the three arms.

Participants who wish to quit smoking will be randomized to

1. Switch to electronic cigarettes containing nicotine plus flavor
2. Switch to electronic cigarettes containing flavor alone Those who do not wish to quit smoking will continue on the Tobacco Cigarette arm Treatment period will be 28 days


Options:
A: Inclusion Criteria:

* smoking at least 10 cigarettes/day in the month prior to admission
* patient has been diagnosed with acute coronary syndrome (includes patients admitted for unstable angina or acute myocardial infarction), elective percutaneous coronary intervention, or coronary artery bypass surgery at any point in time
* motivated to stop smoking
* geographically available for follow-up visits (i.e., live within 1 hour of the study centre)

Exclusion Criteria:

* have been using NRT, Zyban (or Wellbutrin), and/or Champix for more than 72 hours
* have serious cardiac arrhythmias (e.g., tachycardia), vasospastic disease (e.g., Buerger's disease, Prinzmetal's variant angina)
* have severe renal impairment or are on dialysis
* unable to read and understand English
* patient is pregnant or breastfeeding or planning on becoming pregnant during the study period
B: Inclusion Criteria:

* Aged 18 years and over
* Currently smoking ≥15 full strength tobacco cigarettes per day for at least 2 years, or roll-up tobacco equivalent (cigar or pipe smokers not included).
* Willing to stop tobacco cigarettes for period of study if required
* Willing not to use electronic cigarettes if required
* Able to give informed consent

Exclusion Criteria:

* Pregnant or lactating.
* Women of childbearing potential who do not abstain from sex or use effective contraception.
* On current prescribed medication for cardiovascular disease.
* History of cardiovascular disease (excluding hypertension), diabetes, active malignance or chronic renal disease.
* Nut allergy
* Participation in another clinical trial (other than observational trials and registries) with an investigational product and/or intervention within 30 days before visit 1.
C: Inclusion Criteria:

* Be between the ages of 18 and 64
* Purchase exclusively menthol cigarettes
* Not currently motivated to quit smoking
* Smoking a minimum number of cigarettes per day

Exclusion Criteria:

* Report a serious, unstable medical or psychiatric condition
* Use any medications that might interfere with measures to be studied (for example, medications known to affect smoking)
* Have used any smoking cessation therapy during the past month
* Regularly use any form of tobacco other than cigarettes
* Are pregnant or breast feeding or planning to become pregnant or breast feed during the study
D: Inclusion Criteria:

Diagnosis of Schizophrenia or Schizoaffective Disorder Current Cigarette Smoker or History of Chronic Cigarette smoking Age 18-65 Currently taking antipsychotic medication

Exclusion Criteria:

prior history of hospitalization for acute myocardial infarction or stroke, or persistent angina pectoris with current symptoms Patients who have previously tried varenicline and have stopped taking it because of side-effects of severe nausea or vomiting suicide attempt in the last year and or have had prominent or serious suicidal thoughts in the past year Women who are pregnant, nursing, or unable to use reliable contraception significant renal impairment(Creatinine ≥ 1.5) baseline Hamilton Depression Scores is \>20

Answer: B