Question: A randomized controlled trial is conducted to assess the risk for development of gastrointestinal adverse effects using azithromycin compared with erythromycin in the treatment of pertussis in children. Of the 100 children with pertussis enrolled, 50 receive azithromycin, and 50 receive erythromycin. Results show vomiting among 5 patients in the azithromycin group, compared with 15 patients in the erythromycin group. Which of the following best represents the absolute risk reduction for vomiting among patients in the azithromycin group?
A: 0.1
B: 0.2
C: 0.33
D: 0.67
Please eliminate two incorrect options first, then think it step by step and choose the most proper one option. Respond with more than 4 words be in all capital letters.
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