Step 1: Concept
Escape velocity ($v_{e}$) is the minimum speed needed for an object to break free from a planet's gravitational pull without further propulsion.
Step 2: Meaning
It is calculated using the formula $v_{e} = \sqrt{2gR}$, where $g$ is acceleration due to gravity and $R$ is the radius of the planet.
Step 3: Analysis
For Earth, $g \approx 9.8 \text{ m/s}^{2}$ and $R \approx 6.4 \times 10^{6} \text{ m}$. Substituting these values: $v_{e} = \sqrt{2 \times 9.8 \times 6.4 \times 10^{6}} \approx 11,200 \text{ m/s}$.
Step 4: Conclusion
Converting to kilometers, we get approximately 11.2 km/s.
Final Answer: (D)