The Chairman initiated the proceedings with a brief speech.

The correct answer is B. started.

The word “initiated” means to begin or start something. In this case, the Chairman began the proceedings with a brief speech.

The word “complicated” means to make something difficult to understand or do. In this case, the Chairman did not make the proceedings difficult to understand or do.

The word “closed” means to bring something to an end. In this case, the Chairman did not bring the proceedings to an end.

The word “confused” means to make someone feel uncertain or puzzled. In this case, the Chairman did not make the participants feel uncertain or puzzled.

I hope this helps!