Explanation:

- Option 1: Anti-missile defence system

- These systems are used to detect, track, and destroy incoming missiles. They are critical for national defense but are not related to the M777.

- Option 2: Howitzers

- The M777 is a 155mm towed howitzer. Ultra-lightweight, it offers increased mobility to support rapid deployment. The Indian Army acquired these from the USA to enhance its artillery capabilities.

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- Option 3: Fighter jets

- These are aircraft designed mainly for air-to-air combat against other aircraft. Fighter jets are different from howitzers.

- Option 4: Scorpene class stealth fighter jet

- There seems to be confusion here. Scorpene is actually a class of submarines, not fighter jets.

- Option 5: None of the above

- As M777 is a howitzer, this option is incorrect.