GMAT Sentence Correction (SC) | With its abundance of noun inflections, Icelandic is one of

With its abundance of noun inflections, Icelandic is one of several Germanic languages thatis compact when written but can lengthen considerably when translated into English.

(A) is compact when written but can lengthen considerably when translated into English
(B) are compact when they are written, but they can lengthen considerably when they are translated in English
(C) is compact when written but can lengthen considerably when being translated into English
(D) are compact when written but