Final answer:
According to the law of demand, there is an inverse relationship between price and quantity demanded. The correct option is a, stating that price and quantity demanded are inversely related.
Step-by-step explanation:
The law of demand states that there is an inverse relationship between price and quantity demanded. When price goes up, the quantity demanded goes down, and conversely, when price goes down, the quantity demanded increases, assuming all other factors remain constant. This principle is foundational in the field of economics, explaining consumers' purchasing decisions and the allocation of resources. Looking at the options provided, the correct answer is: a. price and quantity demanded are inversely related.