The correct option is "3 only." The Speaker of the Lok Sabha is not appointed at the pleasure of the President; rather, the Speaker is elected by the members of the Lok Sabha themselves, and their tenure is not directly linked to the President's authority. Additionally, the Speaker must be a member of the House at the time of their election; if they are not, they must secure membership within six months after the election. Regarding resignation, the Speaker indeed addresses their resignation to the Deputy Speaker, reflecting the structured hierarchy and procedures within the Lok Sabha. Understanding this structure is crucial for UPSC aspirants as it highlights the governance framework and the roles within India's parliamentary system.