For this question, we are comparing what each author says about the Roma.
Let's go through the answer choices, maybe that will clear things up.
A. This is incorrect, because the author of passage B clearly disapproves of the states' individual right to decide the status of the Roma. See lines 39-42.
B. Incorrect. The main purpose of passage A is to show that international law has failed to properly define a "national minority."
C. The author of passage B doesn't discuss the concept of a nation at all. Incorrect.
D. See my description for A. The author of B prefers standard, empirical rules over the arbitrary rights of individual states to designate a minority.
E. This is the correct answer. It is a fairly broad statement that does apply to both passages. Both authors present the Roma people as a special case that results in a re-evaluation of the laws in place regarding minority designation.
These questions can become confusing when the answer choice says something like, "A, but not B, believes that..." Make sure you highlight main arguments from each passage so that it is easier to compare them. An answer choice has to be correct for both passages. An answer that is half-right may look appealing, but it has to accurately represent both passages.