Solution
= Solution
Set $s=[M]_t$. By hypothesis $s\to\infty$, and part b gives
$$
M_t-\frac12[M]_t=W_s-\frac s2
=s\left(\frac{W_s}s-\frac12\right).
$$
Since $W_s/s\to0$ almost surely, the expression tends to $-\infty$ almost surely.
= Solution
Set $s=[M]_t$. By hypothesis $s\to\infty$, and part b gives
$$
M_t-\frac12[M]_t=W_s-\frac s2
=s\left(\frac{W_s}s-\frac12\right).
$$
Since $W_s/s\to0$ almost surely, the expression tends to $-\infty$ almost surely.