The correct answer is actually D), not A.
Although these are independent clauses indeed, the punctuation in A,B, and C is not correct.
Before 'however' there needs to be a semicolon (;). And after however, you have to put a comma. Therefore D is the correct answer.
After a comma there needs to be a pause in reading. Does A sound correct to you if you make a pause before 'however' and not after it? Of course not.
Answer:
Enlightenment is an intellectual and philosophical movement that dominated the world of ideas in Europe during the 17th and 18th centuries. It was an idea that reason is the primary source of authority and legitimacy, and advocated such ideals as liberty, progress, tolerance, fraternity, constitutional government, and separation of church and state.
Explanation:
I'm not sure if this is what you were looking for, but I tried to decipher your question. So, here is what I came up with.
