$($Computing the expected rate of return and risk$)$ After a tumultuous period in the stock market, Logan Morgan is considering an investment in one of two portfolios. Given the information that follows, which investment is better, based on risk $($as measured by the standard deviation$)$ and return as measured by the expected rate of return?

$\backslash$table$[[$Portfolio A$,$Portfolio B$],[$Probability$,$Return,Probability,Return$],[0\mathrm{.}15,,-3\%,0\mathrm{.}12,3\%$