Supposing my friend didn't send me a promised text by mobile and I run into him today,<br/><br/>Can I say to him, <br/><br/>1]" You could have sent the text to me yesterday" <br/><br/>2]"You could send the text to me yesterday" <br/><br/>3]"You might have been busy yesterday"<br/><br/>4]" You must have been busy yesterday" <br/><br/>5]"You should have been busy yesterday" <br/><br/>I'm not sure whether 2] can be used or not. But except for 2] I think every sentence above can be used. Could you teach me which one I can't use.<br/><br/>Thank you in advance for your teaching.