28. Which of the following investments is preferred by a rational investor : - Investment A:E(R)=8%, standard deviation of returns =3% - Investment B: E(R)=10%, standard deviation of returns =5% - Investment C:E(R)=10%, standard deviation of returns =3% (a) Investment C (b) Investment B (c) Investment A (d) Investment B \& C (e) none as a rational investor would require more information from which to make a decision