Organizations that require customer service representatives to access private customer data can best protect customer privacy and make it easy to access other customer data by using which of the following security controls? A$.$ Preventing customer service representatives from accessing private customer data B$.$ Blocking out customer private data details and allowing access only to the last four digits of Social Security numbers or account numbers C$.$ Encrypting all customer data D$.$ Implementing second$-$tier authentication when accessing customer databases E$.$ All of the above