Non-restrictive appositive" vs. "non-defining relative clause

Non-restrictive appositive" vs. "non-defining relative clause

Could you please kindly provide some explanation as to why the second
option (B) is the only correct answer to the following question? And why
is it not the case that both A and B could be correct depending on whether
a non-restrictive appositive (B) or a non-defining relative clause (A) is
used?
Recently, severe management problems have afflicted Coca-Cola, ____.
A. which is a large multinational corporation
B. a large multinational corporation
C. there is a large multinational corporation
D. a large multinational corporation is it
Your insights, recommendations, and corrections are much appreciated.