State whether the following decision is a short-run or long-run decision:
a. ADM is deciding whether to install machinery that uses Human Machine Interface technology or 8-layer PCB prototype technology in its manufacturing plant.
b. Wal-Mart hires additional seasonal workers during November and December.
c. Bassett furniture manufacturers close all manufacturing plants in North Carolina, USA and outsource their furniture production to manufacturing plants in China.
d. General Motors purchases new equipment to replace depreciating equipment.