Answer:
a) A maker of custom cabinets ⇒ TIME, generally goods that are custom made take longer to produce and clients are aware of this.
b) A producer of automotive spare parts ⇒ CAPACITY, if more parts are needed, you will have to use spare capacity.
c) A hospital emergency room ⇒ CAPACITY, services cannot be stocked, therefore, the only possible buffer is capacity since they cannot make their patients wait in line (a dead person waiting in line is no longer a patient).
d) Wal-Mart ⇒ INVENTORY, whether a store is a brick and mortar or internet retailer, its cheapest safety stock (buffer) is generally inventory.
e) Amazon ⇒ INVENTORY, whether a store is a brick and mortar or internet retailer, its cheapest safety stock (buffer) is generally inventory.
f) A government contractor that builds submarines ⇒ TIME, submarines are very expensive and it takes years to build them, so a week more wouldn't make a difference.
h) A maker of lawn mowers for K-mart and Target ⇒ INVENTORY, the company probably knows when it is going to sell more, so it can add to its inventory of finished goods just in case.
i) A freeway ⇒ CAPACITY and then TIME, services cannot be stocked, and since it takes years to plan and build a highway or freeway, the only possible initial buffer is capacity. But once full capacity is reached, then the only buffer is time.
j) The space shuttle ⇒ INVENTORY, since you cannot go back to Earth just to get refueled, you must carry extra fuel just in case. The same for the rest of the stuff.
k) A business school ⇒ CAPACITY, services cannot be stocked, and no student will wait a few extra years just to get into the school that they love.