Who amongst the following was appointed as Protem Speaker for Sixteenth Lok Sabha?

The answer is B) Kamal Nath. When the 16th Lok Sabha met in June 2014, the President appointed Kamal Nath, the senior-most member of the House, as Pro-tem Speaker. By convention the pro-tem Speaker presides only until the House elects its own Speaker, and during that short period administers the oath to newly elected members.

Why the others are wrong:

• Murli Manohar Joshi and Lal Krishna Advani were senior BJP leaders, but neither was chosen for this role in 2014. Advani had been Leader of Opposition in the 15th Lok Sabha, which is a different post.
• Mallikarjun Kharge was a senior Congress leader and minister, not the Pro-tem Speaker.

The concept is the Speaker's office under Articles 93 to 96 of the Constitution, which requires the House to elect a Speaker after its first sitting. The Pro-tem arrangement is a convention built on seniority. Mains angle: the role of the Speaker in maintaining the neutrality and dignity of the House.

Note that the pro-tem Speaker for the 17th Lok Sabha in 2019 was Virendra Kumar, so the appointment changes with each Lok Sabha.

Trap: Aspirants often confuse the Pro-tem Speaker with the Leader of Opposition or with senior leaders who held prominent posts, and pick the most famous name instead of the senior-most member.