Concentric multi-dimension business strategy refers to the strategy of taking a major product as the center, making full use of the product's technological and market advantages and strengths, and continuously expanding outward to produce multiple products and enrich the product series structure. It is an enterprise Use the original production technology conditions to manufacture new products with different uses than the original products. Based on the above definitions, Which of the following companies use the concentric multi-diagonal business strategy (). ['An automobile manufacturing company explores and expands the market through mergers and holdings. It spends huge sums of money to acquire a well-known foreign automobile manufacturing enterprise and attribute its original high-end products to this well-known brand.', 'An oil exploration and development company refines and refines the petroleum it produces, produces various petrochemical products, and organizes the sales of these products on its own.', 'A clothing manufacturing company is famous all over the country for its unique and innovative design. After its success, it has invested in construction, retail, and other industries to develop into a comprehensive group company.', 'The refrigerator produced by an enterprise has a good refrigeration effect, and its sales volume is in the leading position among similar products in the country. Later, the company produced air conditioners, and the products were also well received by consumers.']