For production of biotechnological product at manufacturing scale bioreactors are used for which all statements are correct except one.

Air bubbles bubbled through the reactor dramatically increase the oxygen transfer area

Sampling ports in bioreactors are meant for adding raw materials into them

Optimum condition for production of biotechnological product like pH, temperature etc. are monitored in them

The stirrer in tank bioreactors helps to mix the reactor contents and facilitates oxygen availability throughout the bioreactor