The two numbers represented in signed $2's$ complement form are $\mathrm{P}=11101101$ and $\mathrm{Q}=11100110$. If $\mathrm{Q}$ is subtracted from $\mathrm{P}$, the value obtained in signed $2's$ complement form is

- $100000111$
- $00000111$
- $11111001$
- $111111001$