Which alternative contains the correct use of the modal verb?
I- I don't know why I am so tired these days. I might be working too hard. Or maybe I am not sleeping too well. II- Do you know where Carl is? He should be out - his car keys are on the table. III- Go and look in the kitchen for your gloves. They can’t be in there. IV- Dan has been drinking that whiskey since early this afternoon. He must be totally drunk by now.
The correct alternative is: