Concept:
• Use substitution: $t = \cot^{-1}x$
Step 1: Substitute
\[
t = \cot^{-1}x \Rightarrow \frac{dt}{dx} = -\frac{1}{1+x^2}
\]
\[
dx = -(1+x^2)dt
\]
Step 2: Substitute in integral
\[
\int \frac{\sin(\cot^{-1}x)}{1+x^2} dx
= \int \sin t \cdot (-dt)
\]
\[
= -\int \sin t \, dt
\]
Step 3: Integrate
\[
= \cos t + C
\]
Step 4: Back substitute
\[
= \cos(\cot^{-1}x) + C
\]
Final Conclusion:
Option (B)