Option 3: (B), (A), (D), (C) -> Along a linear demand curve, elasticity varies continuously from left to right. At the upper left portion (high price, low quantity), demand is elastic with e_d > 1 (B). At the midpoint of the curve, elasticity equals unity with e_d = 1 (A). Moving further right to the lower portion (low price, high quantity), demand becomes inelastic with e_d < 1 (D). Finally, at the extreme right where the curve meets the quantity axis, elasticity is zero with e_d = 0 (C). This represents the fundamental property that elasticity decreases as we move down a linear demand curve. -> correct