The correct option is "2 and 3 only" because the Council of Ministers is indeed collectively responsible to the Lok Sabha, not the entire Parliament, making statement 1 inaccurate. Statement 2 is correct as Union Ministers hold office during the pleasure of the President, following Article 75 of the Constitution. Statement 3 is also correct because the Prime Minister is required to keep the President informed about legislative proposals, an aspect of their advisory role to the President under the framework of the Constitution. This nuanced understanding is crucial for UPSC Prelims, emphasizing the intricacies of the roles and responsibilities outlined in the Indian Constitution.