Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Double-blind, Randomized, Parallel, Placebo-active Controlled, Multi-center Phase II Clinical Trial to Investigate the Efficacy and Safety of YH14642 Following 12-week Oral Administration in Patients With Chronic Periodontal Disease
Brief Summary: This study is designed to evaluate the efficacy and the safety of YH14642 in Korea patients with chronic periodontitis, in order to investigate the recommended therapeutic dose.


Options:
A: Inclusion Criteria:

* \> 20 teeth
* \> 5% sites (approx. 8 sites) with pocket depth \> 4 mm and / or 5% sites with attachment level \> 4 mm and mean AL \< 4.5 mm and mean PD \< 3.9 mm (not including tooth brush abrasions).

Exclusion Criteria:

* \> 50% of sites with pocket depth or attachment level \> 4 mm
* Pregnancy or nursing
* Periodontal or antibiotic therapy in the previous 6 months
* Any systemic condition which might influence the course of periodontal disease or treatment (e.g. diabetes, AIDS)
* Any systemic condition which requires antibiotic coverage for routine periodontal procedures (e.g. heart conditions, joint replacements etc.)
* Liver disease
* Any known allergy to amoxicillin, metronidazole or doxycycline
* Lactose intolerance
B: Inclusion Criteria:

* under 30 years old and systemically healthy, with at least 20 teeth present. Be willing to participate in the study which is corroborated by signing the informed consent form.

Commit to attend post-therapeutic controls and stop drinking alcohol during the time of ingestion of antibiotics.

Exclusion Criteria:

* Subjects in whom are contraindicated or with hypersensitivity to quinolones - Subjects who have undergone periodontal, surgical or mechanical antibiotic therapy six months before the start of the study according to interrogation.

Women in pregnancy or lactation, corroborated with previous medical history and medical consultation.
C: Inclusion Criteria:

* 18 years of age and up
* clinical and radiographic signs of severe (CAL 5 mm or more) chronic periodontitis.
* at least 20 natural teeth in situ
* pocket probing depths (PPDs) of ≥ 5 mm at a minimum of eight tooth sites
* willingness to participate and to be available at all times required for participation
* over 30% of the teeth present must have a PPDs)≥ 4 mm and insertion loss ≥ 5 mm evaluated by an experienced periodontist
* informed consent signed by the patient

Exclusion Criteria:

* if they (or parents or siblings) show confirmed or assumed allergies or hyper-sensitive skin reactions against moxifloxacin, ciprofloxacin (or other quinolones as listed in the "summary of product characteristics, Version Juli 2005"), metronidazole (or other 5-nitroimidazoles and ingredients of Flagyl® 400mg as listed in the "summary of product characteristics, Version Juli 2007"), systemic diseases or conditions as listed in the above mentioned "summary of product characteristics"
* subjects who have undergone antibiotic therapy three months before the start of the study under interrogation
* have Down's syndrome
* known AIDS/HIV
* regularly take systemic medication affecting the periodontal conditions, e.g. phenytoin, nifedipine, and/or steroid drugs
* professional periodontal therapy during 6 months prior to baseline
* require antibiotic treatment for dental appointments
* are pregnant or breastfeeding
D: Inclusion Criteria:

* Subjects must be 20 years of age or older
* Have at least 18 natural teeth
* Four or more clinical attachment level(CAL) ≥ 3mm
* Four or more periodontal pockets with a probing depth (PD) ≥ 4mm
* Have Bleeding on probing
* Provide informed consent and willingness to cooperate with the study protocol

Exclusion Criteria:

* Forbidden History of Panax Notoginseng and Rehmanniae Radix Preparata
* Hypersensitivity of Doxycycline
* Hypersensitivity of Zea mays L. extract
* Critical diseases such as HIV previous three years
* Patients with mental retardation and dementia
* Systemic diseases such as diabetes and hypertension
* Patients who take Anticoagulants or Antiplatelet Agents
* Patients who have malignant tumor
* Smoker
* Continually use for 2weeks of phenytoin, calcium channel blocker, cyclosporin, coumarin, nonsteroidal anti-inflammatory drugs and aspirin use in the previous one month
* Patients who need malignant tumor
* Patients who received periodontal treatment within the last 6 months
* Pregnant or lactating females

Answer: D