Verify whether the following statements are true or false. Completely explain your answer. a) If a good is an inferior good, then it is necessary a Giffen good. b) If a good is a regular good, then it is necessary a normal good. c) Indifference curve is tangent to the budget line for the optimal bundle. d) For a linear demand curve, the elasticity of demand must be different at various points. e) For a downward slopping linear demand curve, the elasticity of demand must be different at various points.