Assume income elasticity (in other words, income elasticity is not equal to 0 or 1). Which of the following statements are necessarily true?As income rises, the amount spent on each kind of inferior good increases As income rises, the proportion spent on each kind of inferior good increases As income rises, the amount spent on each kind of normal good increases As income rises, the proportion spent on each kind of normal good increases As income rises, the amount spent on each kind of necessity good increases As income rises, the proportion spent on each kind of necessity good increases As income rises, the amount spent on each kind of luxury good increases As income rises, the proportion spent on each kind of luxury good increases