Letter D) is correct. You need to have the name as well as the name of the person in the parentheses. Also, it is grammatically correct with all of the commas in the right places.
C. Dr. Juan D'Souza, author of the book The Path to Mozart, says that young children who learn an instrument are more likely to do well in math and science classes when they are older (25).
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.
