a 7% increase in income results in a 3.5% increase in the consumption of milk, then: tion O a. The income elasticity is 2.0, and milk is a luxury good. O b. The income elasticity is 0,5, and milk is a necessity good. O c. The income elasticity is 0.5, and milk is a luxury good. O d. The income elasticity is 2.0, and milk is a necessity good