Which of these changes Earth's climate mainly over time spans of millions of years

The answer is Option B: plate tectonics.

Explanation:

Plate tectonics is a theory about the structure of the earth's crust. In plate tectonics, the continents are viewed as a part of a system of rigid lithospheric plates which move slowly over the underlying mantle of the Earth. The model for plate tectonics builds on the concept of continental drift, which is an idea developed during the first decades of the 20th century. In continental drift theory, all the world's continents were once joined into a land mass that geologists have called Pangea during the late Paleozoic and early Mesozoic eras. It began to break up about 175 million years ago. In the beginning in the late Triassic, the continents began to break up with Laurasia comprising with what is North America and Eurasia and Gondwanaland which was South America and Africa, India, Arabia, Antarctica, and Australia. The shift in plates and their movement create mountain ranges and continents form and move to different latitudes that change the climate as these land masses moved.

b. niger

explanation:

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.