【名词&注释】
逆时针(inverted hour)、总支出(aggregate expenditure)、需求量变动(change in quantity demanded)
[单选题]假设需求的收入弹性系数为0.5,那么当收入变动5%时,需求量变动:()
A. 0.5% B. 2.5% C. 4.5% D. 5.5%