For two events $A , B$,
$$\mathrm { P } ( A ) = \frac { 1 } { 4 } , \quad \mathrm { P } ( B ) = \frac { 2 } { 3 } , \quad A \subset B$$
What is the value of $\mathrm { P } ( A \mid B )$? [3 points]\\
(1) $\frac { 1 } { 8 }$\\
(2) $\frac { 1 } { 4 }$\\
(3) $\frac { 3 } { 8 }$\\
(4) $\frac { 1 } { 2 }$\\
(5) $\frac { 5 } { 8 }$