The "Chemistry in Focus" segment Sugar of Lead discusses $\mathrm{Pb}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}$ , which originally was known as sugar of lead.
a. Why was it called sugar of lead?
b. What is the systematic name for Pb $\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}$ ?
c. Why is it necessary to have a system for the naming of chemical compounds?