Answer:
A.The assertion and the reason are both correct, and the reason is valid.
Step-by-step explanation:
The assertion and the reason that "The movement of Earth's tectonic plates is not responsible for the recent observable climate changes BECAUSE climate changes triggered by shifting plates are extremely gradual and happen on a scale of millions of years" are correct and the reason is valid.
The tectonic plates which was sketched or mapped during the second half of the 20th century.
The word tectonic was also derived from the late Latin word "tectonicus" which means "pertaining to building" is the series of actions that took place in controlling the structure and properties of the earth's crust and how it evolved over time.