The ratio between price and quantity (P/Q) and the magnitude of the elasticity of a demand curve decrease as we move down the curve. At point A, Q = 0, P/Q = ∞, and the price elasticity of demand is –∞. Between points A and B, the demand curve is elastic with a price elasticity of demand less than –1 (more than 1 in absolute value). At point B, the demand curve is unit elastic, or the price elasticity of demand equals –1. Between points B and C, the demand curve is inelastic with a price elasticity of demand greater than –1 (less than 1 in absolute value). At point C, P = 0, P/Q = 0, and the price elasticity of demand equals zero.