A - True. Persuasive writing is all about arguing your point so it has to be true
The sentence given above is A COMPOUND COMPLEX SENTENCE.
A compound complex sentence is a sentence which is made up of at least two independent clauses joined by a conjunction and one dependent clause. In the sentence given above, there are two independent clauses and one depend clause as follows:
1. The first three Harry Potter books landed on the bestseller lists.
2. Both young and adult enjoy the stories.
3. That follow Harry through his challenging life.
Sentence 1 and 2 are independent clauses while sentence 3 is dependent clause.
A conjunction is a word used to connect words or group of words.
A coordinating conjunction joins words or group of words that are similar. They connect words and phrases and also independent clause to form compound sentence.
so the coordinating conjunction in this sentence would be and