Which statement accurately differentiates primary data from secondary data and explains reliability assessment?

Which statement accurately differentiates primary data from secondary data and explains reliability assessment?

• A. Primary data are observations collected by someone else and not by the researcher
• B. Secondary data are always more reliable than primary data
• C. Primary data are original observations collected by the researcher; secondary data analyze primary data; reliability is evaluated by source credibility, methodology, and sample size
• D. Secondary data are never used in health information

Answer: (C)