The correct answer is: B. Luxury.
A luxury good is a good for which the income elasticity of demand is greater than one. This means that when income increases, the demand for luxury goods increases by a greater percentage. For example, if your income increases by 10%, you might spend 15% more on luxury goods.
Inferior goods are goods for which the demand decreases as income increases. For example, if your income increases, you might buy less of a certain type of food because you can now afford to buy more expensive food.
Imperative goods are goods that are essential for survival. For example, food and water are imperative goods. The demand for imperative goods does not change much with changes in income.
Unrelated objects are objects that are not related to each other. For example, a car and a house are unrelated objects. The demand for unrelated objects does not have any relationship to each other.