Which of the following is true?

a. The relationship between price and quantity demanded is inverse, or negative.

b. The market demand curve is the vertical summation of individual demand curves.

c. A change in a good’s price causes a movement along its demand curve.

d. All of these are true.

e. The relationship between price and quantity demanded is inverse, or negative and a change in a good’s price causes a movement along its demand curve are true.