The correct answer is "D".
Due to the growing social unrest against the Communist government in Poland in 1989, a series of talks were held between the banned trade union named "Solidarity" and the government. This laid path to the establishment of a democratic government in Poland, as the office of President and the Senate, was introduced.
Lech Walesa, who at the time was a political activist and leader of "Solidarity", became the President of Poland at the elections of June 4th, 1989.
