The diagram below shows the impact of an indirect tax on the market for petrol, shifting the market supply curve from S1 S_1\,S1 to S2S_2S2.

Which area represents the total reduction in consumer surplus resulting from the imposition of the tax?
Y+ZY + ZY+Z
W+XW + XW+X
W+YW + YW+Y
X+ZX + ZX+Z