Speech balloons, also known as speech bubbles, dialogue balloons or word balloons, are a graphic convention used most commonly in comic books, comics and cartoons to allow words to be understood as representing the speech or thoughts of a given character in the story or events of the graphic novel or Comic.
According to the information presented before I would conclude that the main purpose of a speech bubble in a graphic novel is:
D) It illustrates internal thoughts.
i believe it is B. Better
Based on the excerpt, the statement that best strengthens Feldman´s claim that people are mostly honest is b. Feldman´s payment system was largely successful. His payment system is based on honesty, because he leaves the bagels and a cash basket in which anyone who took a bagel would leave cash, even if people could take a bagel and not pay, or even take money out of the basket, that did not happen. As he says "it was an honor-system commerce scheme, and it worked."
Always treat others in a good manner no matter what their social status is.... at least that's what I learned from it ;)