Answer:
1. You shouldn't leave your ....
2. Someone must have stolen the paintings....
3. You didn't need to ask ....
4.Lousie may have drawn the dragon on the wall.
B.
The importance of money is highlighted when economizing is discussed.
A comma splice is where two independent clauses (complete sentences) are joined together with a comma without also including a conjunction such as "and" or "but." Sentences B and D above both contain comma splices (the comma after "century" in B and the comma after "areas" in D). D is also missing a capital letter at the beginning of the sentence. The problem in sentence C is the commas surrounding the word "however." When the word "however is used to join two independent clauses like this, it should be preceded by a semicolon and followed by a comma. In this sentence, the semicolon belongs after the word "area." The word "however" begins the second independent clause. Thus, the only correct sentence above is A.
It gives specific examples of ways the author can improve the paper.