Answer:
(D) Two of the shop's metalsmiths become ill and are unable to come in to work.
(I also took the test and got it right.)
Step-by-step explanation:
When a curve shifts inward, this indicates that both the equilibrium price and quantity are both decreasing. Therefore, the fact that two of the workers are ill and unable to produce enough product could result in that curve shifting inward or decreasing the supply.