What is the standard deviation of the portfolio with stock A and stock B?

You have a portfolio with a standard deviation of 28% and an expected return of 15%. You are considering adding one of the two stocks in the following table. If after adding the stock you will have 30% of your money in the new stock and 70% of your money in your existing portfolio, which one should you add? Standard deviation of the portfolio with stock A is \%. (Round to two decimal places.)