C and A are on the same curve. C is tangent to a steeper part of the curve.
Steeper parts are usually to the left and represent a smaller bundle of good X in our analysis.
Given these observations when we draw a demand curve for a normal good you will see that it is downward sloping. Relationship Between Inferior and Giffen Goods. A normal good cannot be Giffen. All inferior goods are not always Giffen. All Giffen goods are however inferior.