A study group is asked to prepare a report about the effects of mobile phone use on consumers' hearing. Which of the following sources is most likely to provide relevant data?
A. A university research paper about decibel limits of headphones and speakers
B. A statistical report of mobile phone usage by mobile phone company
C. A professional journal article about the incidence of genetic hearing loss
D. A consumer report about surcharges applied to customers' bills by mobile phone companies
Reports by mobile companies would be biased and a journal about genetic hearing loss would not be related to mobile phone use.
Therefore, the Correct Answer is A.