Please select the eligibility criteria that correspond to the clinical trial below.
Title: The Effect of High Dose N-acetylcysteine on Airtrapping and Airway Resistance of Chronic Obstructive Pulmonary disease-a Double Blinded Randomized Placebo Controlled Trial
Brief Summary: This study is to investigate the add-on effect of high dose NAC (600mg tablet twice daily) on reduction of airtrapping and airway resistance in stable COPD patients as well as to study it's effect in reducing exacerbation, improving exercise capacity and quality of life in stable COPD patients.


Options:
A: Inclusion Criteria:

* Main diagnosis for the Pulmonary Rehabilitation is an International Classification of Diseases-Code J44.- (Other chronic obstructive pulmonary disease) at all 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) Classifications A-D and stages 1-4.

Exclusion Criteria:

* Considerably reduced health status (severe concomitant disease, which will affect the results of the outcome parameters, for example, cancer or severe cardiac, neurological or orthopaedic comorbidities)
* Considerable reduction of sight and hearing
* Severe psychiatric condition as secondary diagnosis
* Lack of ability to speak German
B: Inclusion Criteria:

* Spirometry diagnosed COPD with FEV1/FVC ratio less than 70% and FEV1 less than 80% predicted
* clinically stable and exacerbation free in the past 4 weeks
* history of at least one COPD exacerbation in the past one year

Exclusion Criteria:

* patients allergic or intolerant to NAC
* Recent use of NAC in the past one month
* history of asthma, non COPD respiratory disorders like bronchiectasis, pneumoconiosis or any active pulmonary infection
* patients on long term steroid
* patients on long term oxygen therapy or non invasive ventilation
C: Inclusion Criteria:

* age \> 45 years
* COPD diagnosed by pulmonary function tests during clinical stability, with a ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ≤ 0.70
* clinical stability, defined as at least 4 weeks without antibiotics or oral corticosteroids.

Exclusion Criteria:

* living \>6 months/year outside of the included municipalities,
* living to a distance higher than 500 meters to any of the urban trails used for the study,
* mental disability according to the Mini Mental State Examination in its validated Spanish version
* comorbidity that could interfere with study tests (e.g., lower limb amputation)
* severe psychiatric disease or severe comorbidity limiting survival at one year, according to medical history.
D: Inclusion Criteria:

* Patients with COPD stage 3 or 4, with BODE index ≥ 5
* Hospitalized in the pulmonary rehabilitation unit in the hospital of Morlaix or in the center "Les Acacias" of briançon, with a 3 at 4 weeks pulmonary rehabilitation course;

Exclusion Criteria:

* FEV ≥ 50%
* Pneumonectomy, Lobectomy less than 6 months
* Contraindications to muscle electrostimulation quadriceps
* Absence of written consent
* Inability to follow the respiratory rehabilitation program in its entirety
* People equipped with electronic devices such as pacemakers and intracardiac defibrillators
* Skin lesions and infectious foci on the electrode placement area.

Answer: B