“Vicissitudes” means a change of circumstances or fortune, typically one that is unwelcome or unpleasant.
Option B is the correct answer as it is the most close meaning of the given word in italics, as it means changes of fortune, hence it is correct.
Option A is incorrect because “difficulties” means a lot of hardship in carrying out a task, which is not related to the given word.
Option C is incorrect because “impediments” means a hindrance or obstruction in doing something, hence incorrect.
Option D Is incorrect because it is the change of good fortunes and not just good fortunes.