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 main clause two main clauses one main and one subordinate clause one main and two subordinate clauses

One main and one subordinate clause

Explanation:

While main clauses, also known as independent, are groups of related words expressing a complete thought and therefore, can stand on their own, subordinate clauses do not have a full meaning on their own, and can not stand alone as full sentences. The sentence provided contains one main clause which it's “The Mason-Dixon line has been designated a National Historic Landmark,” and one subordinate clause: “which is perhaps the most famous border ever established by surveying methods,” whose function is to provide additional information about the noun “The Mason-Dixon line,” that is, to act as a non-defining relative clause.

do i dare, or should i, or maybe i should anything similar to these statements would be correct

explanation:

showing or suffering from nervousness, fear, or a lack of confidence