CC Option in Contribution - Email Receipt
Perhaps you could use CiviRules (along with the added extension Email API to enable CiviRules to send emails) not sure though. I don't think CiviCRM provides you facility to choose cc or bcc when sending receipt from offline contribution form(you can add extension and implement buildform and altermailparams hook). However you could achieve this by doing some manual process 


Create contribution and don't send receipt.
Find contribution and select contribution, use 'Print receipt' action
Download the receipt
Use Email to activity to send email with receipt as attachment.


Cheers

Pradeep