In the following table, returns to two assets $($A and B$)$ are given for different states of nature with the stated probabilities of occurring. Calculate the expected $($mean$)$ return, standard deviation of returns for each asset. Which asset would be considered more risky?

State of Nature Probability Return A Return B

$(1)0\mathrm{.}2023\%9\%$

$(2)0\mathrm{.}3511\%6\%$

$(3)0\mathrm{.}407\%-3\%$

$(4)0\mathrm{.}0519\%-6\%$