Drugs A and B are both used for treating a particular skin infection.After one standard application,Drug A eradicates the infection in 95% of both adults and children.Drug B eradicates the infection in 47% of adults and 90% of children.There are otherwise no significant pharmacological differences between the two drugs,and there are no significant side effects.However,the cost of Drug A is twice that of Drug B. Dr. Ram, a general practitioner,always uses drug B for the first treatment,and resorts to Drug A if the infection persists. Dr.Yogesh, another general practitioner,always uses Drug A for adults and drug B for children.Ignoring indirect costs,Which of the following statement is incorrect:

• A. Drug A is more cost- effective than drug B for treating children
• B. Drug A is more effective than B for treating children
• C. Dr.Yogesh's regime achieves a higher level of cost-effectiveness than Dr.Ram's
• D. Drug A is more cost- effective than drug B for treating adults