A mountainous country subject to bitter cold during the winter, eighty

(A) Incorrect. The closing participial phrase “constituting the bulk of its agricultural land in the alluvial soil of valleys and coastal plains” takes as its agent the subject of the preceding independent clause, “North Korea.” However, it does not make sense to say that the country “North Korea” constitutes the bulk of its own agricultural land.

(B) Incorrect. Notice that there is no main verb in the sentence. The present participles “cultivating” and “constituting” are not main verbs. Without a main verb, there is no independent clause, and the sentence is not complete.

Furthermore, “cultivating” and “constituting” seem to take as their agent “North Korea,” and while it makes sense that North Korea is “cultivating staples such as rice,” it does not make sense that North Korea is “constituting the bulk of” its own agricultural land.

(C) Incorrect. The opening appositive phrase, “a mountainous country subject to bitter cold during the winter” incorrectly modifies “eighty percent of North Korea” instead of the entire country of North Korea.

Furthermore, “eighty percent of North Korea is not suitable when growing staple crops such as rice” is vague and doesn’t quite make sense. If this portion of the country “is not suitable,” then how are crops growing there? Not suitable for what, then? Or are the crops growing somewhere else? And could it be land itself, and not farmers, that is “growing staple crops,” as the phrasing seems to indicate?

Lastly, since “which” in “which is cultivated … and constitutes” refers to “rice, this version conveys the illogical meaning that rice constitutes the bulk of North Korea’s agricultural land. Rice is not a type of land, and so, rice cannot constitute the bulk of North Korea’s agricultural land. Logically, the valleys and coastal plains are what constitute the bulk of the agricultural land, and rice perhaps constitutes the bulk of the crops grown on that land.

(D) Correct. Notice that despite being separated from the noun it describes by two relative clauses (“eighty percent of which is not suitable for crop growth, which alluvial soil makes possible”), the opening appositive phrase “a mountainous country subject to bitter cold during the winter” still correctly modifies “North Korea.”

Furthermore, “eighty percent of which” clearly modifies “a mountainous country subject to bitter cold during the winter” and “which alluvial soil makes possible” clearly and logically modifies “crop growth.”

Lastly, “in valleys and coastal plains, such areas constituting the bulk of its agricultural land” makes clear that the valleys and coastal plans are what are “constituting the bulk” of the agricultural land in North Korea.

This version contains no grammatical errors and effectively conveys a logical meaning.

(E) Incorrect. The opening appositive phrase, “a mountainous country subject to bitter cold during the winter” incorrectly modifies “the valleys and coastal plains of North Korea” instead of “North Korea.”

Also, the use of “where” to refer to “land” does not make sense. “Where” should be used to refer to a location, not to a thing like “land.”

Answer: D