Explanation:

TARKASH Exercise

• The exercise named TARKASH by the National Security Guard (NSG) and US Special Operations Forces (SOF) is currently underway in Chennai.

• With chemical and biological warfare being recognised as a coming threat to the world, an ongoing Indo-US joint exercise has for the first time included a Chemical, Biological, Radiological and Nuclear (CBRN) terror response in its drill.

• The objective of the joint exercise was to rapidly neutralise the terrorists, rescue the hostages safely and deactivate the chemical weapons being carried by the terrorists.

Hence option 3rd is correct.