What is the expected yield on the market portfolio at a time when Treasury bills yield $6\%$ and a stock with a Beta of $1\mathrm{.}4$ is expected to yield $18\%?$

Multiple Choice

$10\mathrm{.}8\%$

$8\mathrm{.}6\%$

$14\mathrm{.}6\%$

$12\mathrm{.}0\%$