Final answer:
The demand curve shows the relationship between product demand and product price, and typically slopes downward from left to right.
Step-by-step explanation:
The true statement about the demand curve is that it shows the relationship between product demand and product price. Demand curves generally slope downward from left to right because as the price increases, the quantity demanded decreases, and vice versa. While demand curves can have different shapes, they all follow the law of demand.