Tectonic plates are more common in California
I believe that the answer is C. This is most likely the best option because it also adds a subject. B does add a better description but putting "While I" in answer C shows who is listening to the sentence
"Isn't" is the best option from the list in terms of completing these sentence. This is primarily because "isn't" is a contraction of the two words "is" and "not.
Landed or descended is the best option as that is the meaning of alighted
