An online logistics firm employs delivery couriers. According to the marginal productivity theory of labour and the principles of derived demand, which of the following changes is most likely to make the firm's demand for couriers more wage elastic?
A transition from the short run to the long run, during which the firm can invest in autonomous delivery drones to replace couriers.
A decrease in the price elasticity of demand for the firm's delivery services, due to a successful brand loyalty campaign.
An increase in the price of fuel and logistics warehouses, which causes courier wages to represent a significantly smaller proportion of the firm's total costs.
A decrease in the price elasticity of supply of alternative delivery technologies, making automated sorting machinery rapidly more expensive to acquire as demand for it rises.
