I believe your answer is B.
Answer:
That would be A
Explanation:
Adding "in" to the word substantial would result in a word meaning the opposite.
1.) A comma can connect sentence 1 and 2.
2.) B.)
3.) A.)
4.) D.)
5.) D.) (I think so)
C is the correct answer I think.
Hope this helps!!!
A. in the palaces of chinese emperors