Statement 1 is Incorrect: The Chairperson of the Committee on the Welfare of Scheduled Castes and Scheduled Tribes is appointed by the Speaker of the Lok Sabha from amongst its members, not by the Chairman of the Rajya Sabha.

Statement 2 is Incorrect: The Committee consists of 30 members, out of which 20 are elected by the Lok Sabha and 10 are elected by the Rajya Sabha, not the other way around.

Statement 3 is Incorrect: A Minister is strictly ineligible to be elected as a member of this Committee. If a member is appointed as a Minister after their election, they immediately cease to be a member of the Committee. There is no exception for the Union Minister of Social Justice and Empowerment or any other minister.

Statement 4 is Incorrect: The term of office of the members of the Committee does not exceed one year, not two years. It is reconstituted annually like other major standing parliamentary committees (e.g., Public Accounts Committee, Estimates Committee).

Since all the statements are incorrect, there is no correct statement. Therefore, the correct option is D.