Example 2 (10th "Hope Cup" Invitational Competition Question) In the complex plane, the largest interior angle of the triangle formed by the points corresponding to the complex numbers $\frac{1}{\mathrm{i}}, \overline{\mathrm{i}-1},(\mathrm{i}-1)^{3}$ is equal to ().
A. $\pi-\arccos \frac{2}{\sqrt{13}}$
B. $-\arccos \frac{2}{\sqrt{13}}$
C. $45^{\circ}$
D. $120^{\circ}$
Solution: Choose A. Reason: Since $\frac{1}{i}=-\mathrm{i}, \overline{\mathrm{i}-1}=-1-\mathrm{i},(\mathrm{i}-1)^{3}=$ $2+2 \mathrm{i}$, thus the points $A, B, C$ corresponding to them in the complex plane are as shown in Figure $9-2$.
The largest interior angle of $\triangle A B C$ is $\angle A$, its size is
$$
\begin{aligned}
\arccos A & =\arccos \frac{B A^{2}+A C^{2}-B C^{2}}{2|A B \cdot A C|} \\
& =\arccos \frac{1+13-18}{2 \sqrt{13}} \\
& =\arccos \left(-\frac{2}{\sqrt{13}}\right)=\pi-\arccos \frac{2}{13} .
\end{aligned}
$$