What does the term "Just$-$In$-$Time" $($JIT$)$ refer to in operations management?

a$)$ Minimizing inventory levels by receiving goods only as they are needed in the production process

b$)$ Stockpiling large quantities of raw materials to ensure continuous production

c$)$ Using advanced technology to automate all aspects of production

d$)$ Outsourcing production to other countries to reduce costs