What serves as a good example of the notion that people were aware of some of the chemical processes involved in photography centuries before they were really developed. A. silver nitrate being discovered by albertus magnus in the 13th century

B. lernarodo da vinci using developer to produce real camera prints

C. the greek philosopher aritstotle writing lengthy essays about the processes of the photography

D. cave drawings that clearly depict modern day camera and photography processes

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 a. primary sources are historical documents, and secondary sources are modern-day documents.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.