Answer:
The best place to separate the run-on sentence in two sentences is "after wild", that is, option A.
Step-by-step explanation:
After the word "wild" is the best place to separate the run-on sentence above in two sentences because the other independent clause starts after that word. "The crown went wild" is one of the independent clauses and the other one is "They screamed so loudly that I could barely hear myself think". You can see, that these are independent clauses because they can stand alone as a sentence as they represent a complete thought. Therefore, the sentence above would be as follows: The crowd went wild. They screamed so loudly that I could barely hear myself think.