The answer is "D. a secondary source summarizes complex subjects by synthesizing multiple sources".
A primary source gives immediate or firsthand proof around an occasion, protest, individual, or masterpiece. primary sources incorporate verifiable and authoritative archives, observer accounts, consequences of trials, measurable information, bits of exploratory writing, sound and video chronicles, addresses, and workmanship objects.
Secondary sources depict, talk about, translate, remark upon, investigate, assess, outline, and process essential sources. Secondary source materials can be articles in daily papers or well known magazines, book or motion picture audits, or articles found in insightful diaries that talk about or assess another person's unique research.