Belgrade is widely known as the capital city of Serbia, but it is a

OFFICIAL EXPLANATION






• Split #1: oldest vs. older

Old, older, oldest

Older is a comparative adjective that is used when two items are at issue.
Oldest is a superlative adjective that is used when more than two items are at issue.

Native speakers frequently (and, in a strict sense, incorrectly) use "older" to describe a member of a set with more than two items.
In terms of usage, err on the side of caution on the GMAT, whose writers still maintain, as do I, a distinction between the older of two and the oldest of three or more.

Are there more than two cities in Europe? Yes.
Use oldest, not older
Eliminate options C, D, and E.

• Split #2: nevertheless—fragment or usage error

The second part of option B is not actually attached to the first part and misuses nevertheless.
The sentence looks like a weird run-on.
We need a conjunction (and, but, or yet) to connect the three pieces of information about Belgrade.
Nevertheless is not a conjunction. (It can be a conjunctive adverb, though it is not so here. See below.)


Here is option B in the sentence:
→ → Belgrade is widely known as the capital city of Serbia, nevertheless also one of the oldest cities in Europe and the largest in the territory formerly known as Yugoslavia.
Nevertheless is a contrast word whose meaning is similar to however.
Nevertheless is also an adverb.

That adverb is not well suited to the goal of the sentence.
The sentence is trying to connect three pieces of adjectival information about Belgrade, a noun.

On one hand, Belgrade is (=) widely known as the capital of Serbia.
On the other hand [and, tacitly, less widely known, hence the contrast word "but"], Belgrade is also one of the oldest cities in Europe and the largest in the former Yugoslavia.

The word nevertheless cannot conjoin those adjective phrases in the way attempted in option B.
This fact might be easier to see if we replace nevertheless with its close synonym, however.
→ → Wrong: Belgrade is widely known as the capital city of Serbia , however also one of the oldest cities in Europe and the largest in the territory formerly known as Yugoslavia.
Read that sentence out loud to yourself. It should sound strange. It is strange.
A verb is missing from the second part of the sentence and the two parts of the sentence are not connected.

If you want to use nevertheless as a conjunction to join two ideas, you cannot just toss in the word nevertheless in any way you wish.

In the case that you want to make it a conjunction, nevertheless must become "conjunctive adverb" (or "connective adverb") to which are attached very specific rules:

1) it must join two fully independent clauses (the second part of option B is not a clause because it does not have a verb), and
2) it must follow a semicolon or period—not a comma.

Option B fails on both counts.
Corrected : Belgrade is widely known as the capital city of Serbia; nevertheless, Belgrade is also one of the oldest cities in Europe and the largest in the territory formerly known as Yugoslavia.
[Note the inclusion of a new subject and verb so that the second part is an independent clause.]

We might also say (again, adding the verb "is" to the second part of the sentence), correctly: Belgrade is widely known as the capital city of Serbia but nevertheless is also one of the oldest cities in Europe.
The diction in both sample sentences is strange.
We do not typically use nevertheless in this kind of "yes, but don't forget about the other part" situation.

In this prompt, we do not really want a word whose usual meaning is "in spite of the fact that."

This example of nevertheless displays more typical usage and diction:
She possessed a wretched sense of direction; nevertheless, she walked around the unfamiliar city as if she knew exactly where she were going.

Option B fails because it lacks a conjunction to join its two parts; because nevertheless is used improperly; and because the second part of the sentence is nonsensical.

Now, if you do not like any of that analysis, I have a question.
Why is option B better than option A? (Answer: it is not.)

Eliminate B.

The correct answer is A.

Comments

ElninoEffect and kaptainklutz (both of you chose great usernames), welcome to SC Butler.

I am always glad to see new people join the SC Butler crew.
All aspirants have a standing invitation to post. (Big Hint to shy people.)

These answers are all spot on.
Keep up the hard work.