When the annual Union Budget is not passed by the Lok Sabha,

The correct answer is D because the passage of the Union Budget is a matter of confidence in the government. In a parliamentary democracy, the Council of Ministers is collectively responsible to the Lok Sabha. The inability of the government to pass its annual financial statement or budget indicates that it has lost the support of the majority in the lower house. Consequently, the Prime Minister and the entire Council of Ministers must resign, as it is equivalent to losing a no confidence motion. Options A, B, and C are incorrect because the failure to pass the budget is a constitutional crisis that cannot be resolved simply by modifying the document or replacing an individual minister.