Explanation
Correct answer: A.
Choice A is the best answer. This choice uses a comma and a coordinating conjunction (“and”) to join two independent clauses (“The Tantaquidgeon…Tribe” and “Today…country”).
Why the other choices are wrong
Choice B
Choice B is incorrect. This choice results in a grammar error known as a run-on sentence. The clauses before and after “Tribe” are both independent, so they need to be separated with some sort of punctuation.
Choice C
Choice C is incorrect. This choice results in a grammar error known as a run-on sentence. The clauses before and after “and” are both independent, so they can’t be linked with just a conjunction. A comma would also be required.
Choice D
Choice D is incorrect. This choice results in a grammar error called a comma splice. The clauses before and after “Tribe” are both independent, so they can’t be linked with just a comma. A coordinating conjunction like “and” or “but” would also be required.