Please show work.

You consider 4 stocks with the following correlations Corr(1,2)=0.25;Corr(1,3)=0.60;Corr(1,4)=0.45. Each stock has the same expected return of 10% and standard deviation of 20%. Assume your portfolio currently has only $100,000 of stock 1. You would like to invest another $100,000 in only one stock (2,3, or 4). Which stock (you choose only one stock among 2,3 , and 4) would be the best to add to your current portfolio. Justify your answers. Calculate the expected return and standard deviation of your new portfolio after adding that stock