Explanation:

- Option 1: Treachery

- Treachery means betrayal of trust, but is not a specific legal offence for betraying the nation under Indian law.

- Option 2: Sedation

- Likely a typo for "Sedition," which refers to inciting rebellion against the government, but not exactly betrayal of the nation.

- Option 3: Treason

- Treason is the act of betraying one's country, especially by attempting to kill or overthrow the sovereign or government. In India, it's a serious offence and can be punishable by death under relevant laws.

- Option 4: None of the above

- Incorrect, as treason directly fits the definition in the question.

Correct Answer: Option 3 – Treason.