Which of the following is a tectonic activity?

• A. Earthquakes
• B. Weathering
• C. Erosion
• D. Sedimentation

Answer: (A)

Earthquakes are a tectonic activity because they come from the movement of the Earth's lithospheric plates. When plates grind, collide, or pull apart, they store up elastic energy in rocks. When that energy is released suddenly along faults, the rocks snap and seismic waves ripple through the ground, causing shaking. This direct link to plate movement is what makes earthquakes a tectonic process.

Weathering, erosion, and sedimentation are surface and near-surface processes driven by climate, gravity, and water flow. Weathering breaks rocks down in place, erosion transports the debris, and sedimentation deposits it in layers. While tectonics can shape landscapes that influence these processes, they are not themselves caused by plate motion in the same way earthquakes are.