Lean production is a technology that minimizes waste and reduces inventory and shortens the production cycle through changes in system structure, personnel organization, operation methods, and market supply and demand. The ultimate goal is to optimize the overall process through low-cost processes. , Balanced logistics, efficient use of resources, elimination of all inventory and waste, to achieve the purpose of providing customers with the most perfect value with the least investment. According to the above definition, Which of the following are lean production:. ['In order to seize the market, Company A keeps improving space utilization.', 'Company B invested a lot of money to shorten its production cycle.', "Company C's strong supply system ensures that it can meet customers at any time.", 'Ding company fully utilizes its own advantages to establish an ultra-fast logistics system.']