Answer:
D
Step-by-step explanation:
The first event caused an increase in the cost of production, then producers with the same amount of resources could produce less and for instance the total supply decreased (shifted to the left). Three months later, production process was optimized because with fewer raw materials the firm could produce the same number of units. This caused an increase in the total supply (shift to the right) because with the same resources, firms can produce more units. We do not know the magnitude of this changes, then we cannot affirm that the second event increased supply above what it had been originally because the second event could counteract the first event.