Question

The following sentence contains _____.

The Mason-Dixon line, which is perhaps the most famous border ever established by surveying methods, has been designated a National Historic Landmark.

one noun clause
one adjective clause
one adverb clause
no subordinate clauses

Answer 1

In my opinion, the correct answer is B. one adjective clause. This clause is "which is perhaps the most famous border ever established by surveying methods". It modifies the subject ("The Mason-Dixon line"), providing an additional description for it.