What does a conclusion do? a). ideas to the writers purpose b). restates the introduction

The conclusion of a paper serves to "tie up the loose ends" of the paper. In no circumstance should a conclusion introduce new ideas to the paper, so the answer is B. For prose purposes, and just a better paper overall, don't directly restate the introduction - for that matter, try to write the conclusion so that it encapsulates ideas from the introduction but complements it rather than restates it.