To produce in large quantities, the development of bioreactors, where large volumes _____ of culture can be processed, is required.

100-1000 litres

The correct answer is Option (3) → 100-1000 litres 

Bioreactors serve as large vessels designed for the large-scale cultivation of cells to produce specific gene products for commercial purposes. Small volume cultures cannot yield appreciable quantities of products. To produce in large quantities, the development of bioreactors, where large volumes (100-1000 litres) of culture can be processed, was required.

Thus, bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes, etc., using microbial plant, animal or human cells. A bioreactor provides the optimal conditions for achieving the desired product by providing optimum growth conditions (temperature, pH, substrate, salts, vitamins, oxygen).