What is tectonics concerned with?

Tectonics is primarily concerned with the movement and interaction of the Earth's lithosphere, which is the outer layer of the Earth composed of the crust and the upper mantle. This field of study focuses on the processes that shape the Earth's surface, such as plate tectonics, where large plates of the Earth's crust move and interact with one another. This movement can lead to various geological phenomena, including earthquakes, volcanic activity, mountain formation, and the creation of ocean trenches.

The other options deal with different scientific concepts. Ocean currents refer to the large-scale movement of water in the world's oceans, climate change involves shifts in atmospheric conditions over time, and photosynthesis is the process by which plants convert light energy into chemical energy. While all these topics are important in their respective fields, they do not relate to the study of the movements of the Earth's crust, which is the central focus of tectonics.