The correct option is B You shouldn't criticize others when you too have your own weaknesses.
A proverb is a short saying that states a general truth or advice.
They're popular as they are told and retold through generations,
incorporated in books and stories that grandparents narrate to children. Proverbs have a deeper meaning than the one you perceive at first. The given proverb is a very old saying and is famous as well, as it's been used often to produce a dramatic effect. It's an advice against people whose own structures (pertaining to personality and deeds) are weak (glass houses), such people should not bring out the flaws of another (throw stones). Option B provides the same meaning, hence it's correct. Options A, C and D do not provide the actual meaning of the proverb, they state things of common sense, hence A, C and D are incorrect.