The standard English proverb is "A fool and his money are soon parted," meaning a foolish or careless person tends to spend or lose money quickly, often because he does not think carefully before spending. Among the given options, "A fool and his money are parted easily" keeps the correct subject pairing, a fool and his money, joined by are parted, which matches the structure and sense of the real proverb most closely.
Option 1, "A fool is always parted from his money," changes the structure so that only the fool is the subject, losing the paired phrasing that makes the proverb recognizable. Option 3, "Money and the fool must part ways," reverses the order and adds the idea of an obligation, must, which is not part of the original saying. Option 4, "You can always part a fool from his money," turns the proverb into an active statement about a third person's action, rather than the passive observation the proverb makes.
Option 2 stays closest to the accepted proverb in both structure and meaning, so it is the correct choice.