f a portfolio regularly rises when a benchmark index rises, but it rises less than the benchmark does, the portfolio's beta coefficient could be $\_\_\_\_\_\_\_\_\_\_.$

A$.)$

$-0\mathrm{.}5\%$

B$.)$

$-1\mathrm{.}0\%$

C$.)$

$0\mathrm{.}5\%$

D$.)$

$1\mathrm{.}0$