Concept:Price elasticity of demand shows how strongly quantity demanded reacts to a change in price.Explanation:Use the formula:Ed=%change in price%change in quantity demandedQuantity demanded falls by 5%, so the change is −5%.Price rises by 10%, so the change is +10%.Substitute the values: Ed=+10%−5%=−0.5Elasticity is usually reported as a positive number, so we take the absolute value.Thus, Ed=0.5.Answer:The price elasticity of demand is 0.5.Therefore, Option A is correct.