An individual$$s utility function is $()$ where $$ is her uncertain income, and $$ is increasing and concave. Which of the following statements is correct? $($a$)$ she exhibits decreasing absolute risk aversion whenever $3()30($b$)$ she exhibits decreasing absolute risk aversion if she is prudent $($c$)$ she exhibits decreasing absolute risk aversion if $3()30($d$)$ she exhibits decreasing absolute risk aversion only if she is prudent