Which of the following is the best description of tectonic plate movement at a transform boundary? A. The collision of the plates results in the formation of mountains. B. Separation of the plates causes rising magma and seafloor spreading. C. The plates grind past each other, producing seismic waves. D. One plate slides beneath the other and begins to melt.

To determine the best description of tectonic plate movement at a transform boundary, let's analyze each option: A. **The collision of the plates results in the formation of mountains.** - This describes a convergent boundary, where plates collide and can form mountains. B. **Separation of the plates causes rising magma and seafloor spreading.** - This describes a divergent boundary, where plates move apart, allowing magma to rise and create new oceanic crust. C. **The plates grind past each other, producing seismic waves.** - This accurately describes a transform boundary, where two plates slide past one another horizontally, often leading to earthquakes. D. **One plate slides beneath the other and begins to melt.** - This describes a subduction zone, which is characteristic of convergent boundaries. Based on this analysis, the best description of tectonic plate movement at a transform boundary is: **C. The plates grind past each other, producing seismic waves.**