Laos has a land area about the same as Great Britain but only 4 million in population, where many are members of hill tribes ensconced in the virtually inaccessible mountain valleys of the north.
A. about the same as Great Britain but only 4 million in population, where many
B. of about the same size as Great Britain is, but in Laos there is a population of only 4 million, and many
C. that is about the same size as Great Britain’s land area, but in Laos with a population of only 4 million people, many of them
D. comparable to the size of Great Britain, but only 4 million in population, and many
E. comparable to that of Great Britain but a population of only 4 million people, many of whom
Ans is E, I chose C.
I can not figure out the sentense structure. Say, "a population of only 4 million people" after "but" is used for what?