If the price for a good increases, its quantity demanded will decrease and the demand for the complements of that good will also decline. For example, if the price of hot dogs increases, one will buy fewer hot dogs and therefore demand fewer hot dog buns, which are complements to hot dogs.
The correct option is: b. a change in the price of the good or service.
The curve shifts to the right if the determinant causes demand to increase. This means more of the good or service are demanded even though there's no change in price. When the economy is booming, buyers' incomes will rise.
The correct answer is C. A change in the price of a good does not shift the demand curve.