input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** For calculation of sample size for a prevalence study all of the following are necessary except   (A) Prevalence of disease in population   (B) Power of the study   (C) Significance level   (D) Desired precision
output: ['(D) Desired precision <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Prevalence of disease in population  (B) Power of the study  (C) Significance level  (D) Desired precision <> possible answers', '  For calculation of sample size for a prevalence study all of the following are necessary except <> context']