Senior Member. a) mass production(often hyphenated) is the correct noun here.

Is mass produced one word?

verb (used with object), mass-pro·duced, mass-pro·duc·ing. to produce or manufacture (goods) in large quantities, especially by machinery.

Is mass produced?

Mass production is the manufacturing of large quantities of standardized products, often using assembly lines or automation technology. Mass production facilitates the efficient production of a large number of similar products.