Two investment advisers are comparing performance. One averaged a $21\%$ rate of return and the other a $18\%$ rate of return. However, the beta of the first investor was $1\mathrm{.}4,$ whereas that of the second investor was $1.$

Required:

a$.$ Can you tell which investor was a better selector of individual stocks $($aside from the issue of general movements in the market$)?$

b$.$ If the $T-$bill rate was $7\%$ and the market return during the period was $13\%,$ which investor would be considered the superior stock selector?

c$.$ What if the T$-$bill rate was $4\%$ and the market return was $17\%?$

Answer choices $($First investor, second investor, undetermined$)$