Read the Passage carefully and answer the questions.

The DNA fragments can be separated by a technique known as gel electrophoresis. Since DNA fragments are negatively charged molecules, they can be separated by forcing them to move towards the anode under an electric field through a medium/matrix. The separated DNA fragments can be visualised only after staining the DNA with a compound known as ethidium bromide followed by exposure to UV radiation. The repeated amplification of DNA is achieved by the use of a thermostable DNA polymerase (isolated from a bacterium, Thermus aquaticus). After completion of the biosynthetic stage, the product has to be subjected through a series of processes before it is ready for marketing as a finished product. The downstream processing and quality control testing vary from product to product. The convention for naming restriction enzymes is the first letter of the name comes from the genus and the second two letters come from the species of the prokaryotic cell from which they were isolated.

The thermostable DNA polymerase is isolated from -

Thermus aquaticus

The correct answer is Option (3) → Thermus aquaticus 

Taq polymerase is the heat-stable (thermostable) DNA polymerase extracted from the thermophilic bacteria Thermus aquaticus. Its predominant function is in the polymerase chain reaction (PCR) technique, where it automates the repetitive step of amplifying specific DNA sequences. The polymerase chain reaction can multiply DNA molecules by up to a billion-fold. This produces large quantities of specific genes with downstream use across multiple applications.