The diagram below shows a shift in the market supply curve for electric delivery vans from S1 S_1\,S1 to S2S_2S2.
Which of the following is most likely to have caused this shift?
A rise in the market price of electric delivery vans.
An increase in import tariffs on lithium-ion batteries.
A government subsidy granted to manufacturers of electric vans.
A reduction in the productivity of assembly line workers.
