According to statistics, compared with last year, the number of influenza patients has decreased significantly since January this year, thanks to the invention and put into use of new special effects drugs. Which of the following can best refute the above conclusions? ['February is the high incidence of influenza.', 'Influenza patients rarely go to the hospital for treatment.', 'Influenza virus is resistant.', 'New high-efficiency medicines are priced high and patients use less.']