This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Pharmacology, Subject name: Pharmacology
Number of patients in Phase II clinical trial: 
Select and explain. 
A. 10-100, B. 200-400, C. 1000-2000, D. 2000-4000
B: 200-400
Answer: B: 200-400 
Explanation: (Ref: Goodman & Gillman 13th ed. P 6)Clinical Trials and its characteristicsPhase I first in humanPhase II first in patientPhase III multisite trialPhase IV post marketing surveillance10-100 participants50-500 participantsA few hundred to a few thousand participantsMany thousands of participantsUsually healthy volunteers; occasionally patients with advanced or rare diseasePatient-subjects receiving experimental drugPatient-subjects receiving experimental drugPatients in treatment with approved drugOpen labelRandomized and controlled (can be placebo controlled); may be blindedRandomized and controlled (can be placebo controlled) or uncontrolled; may be blindedOpen labelSafety and tolerabilityEfficacy and dose rangingConfirm efficacy in larger populationAdverse events, compliance, drug-drug interactions1-2 years2-3 years3-5 yearsNo fixed durationUS $10 millionUS $20 millionUS $50-100 million-Success rate: 50%Success rate: 30%Success rate: 25%-50%-Maximum drug failure occur in this phase: Phase IIMost important phase of clinical trial: Phase IIIA new drug is launched in market after phase IIIPhase 0 trial is microdosing study, done on normal healthy volunteers. To study the PK/PD of drug by radio labelling and administering.Phase 5 clinical trial is Pharamcoepidemiology.Phase 0 and 1 done on normal healthy volunteers.