Two events $A$ and $B$ are independent, and
$$\mathrm{P}(A \cap B) = \frac{1}{4}, \quad \mathrm{P}(A^C) = 2\mathrm{P}(A)$$
Find the value of $\mathrm{P}(B)$. (Here, $A^C$ is the complement of $A$.) [3 points]\\
(1) $\frac{3}{8}$\\
(2) $\frac{1}{2}$\\
(3) $\frac{5}{8}$\\
(4) $\frac{3}{4}$\\
(5) $\frac{7}{8}$