Which of the Following Best Explains 'Just-In-Time Management (JIT)

Which of the following best explains 'just-in-time management (JIT) '? 

A)  Only raw materials and components are kept in stock. 
B)  All activities are planned based upon customer order. 
C)  There is no stock held at all the purchase and order of materials takes place on the basis of the specific customer order. 
D)  All materials and products become available at the very moment when they are needed in the production process.