Explanation:

- Option 1: Speaker of Lok Sabha – The Speaker has no constitutional role in advising the President on emergency proclamations.

- Option 2: Prime Minister – While the Prime Minister is head of the government, the President cannot act solely on their advice for this matter.

- Option 3: Chief Justice of India – The judiciary does not have an advisory role regarding the proclamation of emergency.

- Option 4: Union Cabinet – The Constitution (Article 352) requires the President to act on the written advice of the Union Cabinet, NOT just the Prime Minister alone.