(Answer in 8 - 15 sentences.) A portfolio with the stocks of the 500 largest US corporations is safer than a portfolio with the stocks of the 2,000 smallest companies traded on the New York Stock Exchange: historically, the former portfolio has a return variance (_P²) of around 0.039 versus a return variance of around 0.100 for the latter. A possible explanation for this fact is that, individually, large corporations have less unique risk than small corporations. Do you agree with this explanation? Either support or refute this explanation using strongest arguments you can muster. Be precise.