What is the main difference between primary and secondary sources?
A.
Primary sources are historical documents, and secondary sources are modern-day documents.
B.
Primary sources are derived from museums and archives, and secondary sources are created by history students and academics.
C.
Primary sources are found in ancient places with a rich history, and secondary sources are found in historical journals and blogs.
D.
Primary sources are created during a particular historical era, and secondary sources are created by studying primary sources.