Which of the Following Is True

Which of the following is true?

A) The market demand curve for a product is the vertical summation of the demand curves of the individuals in the market.
B) A fall in a good's price leads to a decrease in quantity demanded, illustrated by moving along a demand curve.
C) According to the law of demand, other things equal, when the price of a good or service falls, demand increases.
D) A change in demand for chocolate bars is caused by a change in the price of chocolate bars.
E) None of the above is true.