Right answer is (a) Batch fermentation
Explanation: The medium can be sterilized by employing batch or continuous sterilization techniques. The fermentation is started by inoculating the medium. The growth conditions (pH, temperature, O2 supply, nutrient addition) are maintained at optimal levels. The froth formation can be minimised by adding antifoam agents. The production of enzymes is mostly carried out by batch fermentation and to a lesser extent by continuous process.