Question

Which sentence is punctuated correctly?

A) Robert wanted a new car however, he couldn't afford to buy one.

B) Robert wanted a new car however; he couldn't afford to buy one.

C) Robert wanted a new car; however he couldn't afford to buy one.

D) Robert wanted a new car; however, he couldn't afford to buy one.

Answer 1

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 2

Answer:

D) Robert wanted a new car; however, he couldn't afford to buy one.

Explanation:

Two sentences can be joined with a semi-colon. The conjunctive adverb "however" must be followed by a comma. Robert wanted a new car; however, he couldn't afford to buy one. is correct.

I just did it on usatestprep.

Hope this helps!!!