Which example of dialogue is punctuated correctly? "be careful, because the floor is wet," he warned. "be careful, because the floor is wet", he warned. "be careful, because the floor is wet" he warned. "be careful, because the floor is wet." he warned.

"Be careful, because the floor is wet," he warned.

Explanation:

This is correct because if you add a period after the word wet, it shows that the sentence is over and does not connect with he warned.

The last sentence

Explanation:

I do not know if I'm right but I think it's the last one because it's the only one that tells us who it was or what it was that warned us that it's flat was wet

i guess you are missing the idea that has to be supported, am i right?