Please explain!

You are considering investing in a portfolio of 4 stocks from four different industries. Which of the following statements is logical? You should be able to significantly diversify away systematic (market) risk. The covariance of the stocks should be quite low I] The correlation coefficient of the stocks should be quite high V Other factors equal, the portfolio standard deviation should be lower than would be the case where the stocks are from the same ndustry [M Other factors equal, the portfolio mean should be lower than would be the case where the stocks are from the same industry M You should be able to significantly diversify away unsystematic risk None of the above