In studying pre-industrial Europe, these historians have focused on only the 2 or 3 percent of the population that comprised the political and social elite, but they have generally overlooked the rest, thereby failing to understand European civilization as a whole.
Things to notice before moving on to the options :
1) but they have generally....... pronoun 'they' must refer to an antecedent , which is plural.
2) parallelism eg. Scientists
have studied the climate, but they
have overlooked the global warming.
(A) In studying pre-industrial Europe, these historians have focused on--
seems correct .. let's save it for the end. (B) Studies of pre-industrial Europe by these historians have been focused on..
'they' can refer to the studies as well as historians. And also, studies cannot 'fail' to understand the European civilization, but the historians are failing to understand European civilization.(C) Studying pre-industrial Europe, these historians
have had as a focus(D) These historical studies of pre-industrial Europe
have had as a focus(E) In their study of pre-industrial Europe, historians
have been focusing on - this option clearly breaks the parallelism as mentioned above.
In studying pre-industrial Europe,
these historians have focused on only the 2 or 3 percent of the population that comprised the political and social elite,
but they have generally
overlooked the rest, thereby failing to understand European civilization as a whole.