Explanation:

All of the above

The most popular methods of containing the pest include the use of Genetically Modified (GM) crops and pesticides.

• Natural approaches, including breeding predators such as wasps, to be released into fields when necessary, as well as developing a “germ warfare” that isolates diseases to which the caterpillar (armyworm) is prone, are being explored by the scientists.
• A quarantine system, under which imports of grains and plants that can host such insects are inspected at shipping ports, airports and land border crossings is the first line of defence taken by the countries across the world. 
• The quarantine system in India is governed by the Plant Quarantine (Regulation of Import into India) Order of 2003, which is notified under the Destructive Insects and Pests Act of 1914.

Hence option 4th is correct.