Because my car can accommodate only four passengers and their luggage.
a. fragment
b. run-on
c. correct

Your answer would be A (a fragment). This is because the sentence is not coherent without the subject and abruptly begins as if there should be another sentence in front of it. Hope this helps :) 

The details about the statues, i believe, are that they're carved from blocks of igneous stone, many of them are partially buried under the ground which to preserve and protect them from the harsh environment on easter island, and many of the facial features have washed away. also, the most well-preserved one is at the british museum in london.these are just guesses from what i can see and what i think i read correctly. i'm sorry i couldn't be more .

Writing since he was a writer