Which of the Following Is True About Elaborative Rehearsal

Which of the following is true about elaborative rehearsal?  

A) It involves visually representing a list of letters that needs to be remembered. 
B) It involves mentally repeating a list of letters or numbers that needs to be remembered. 
C) It involves adding additional letters to a list of letters that has already been memorized. 
D) It involves extending the semantic meaning of the letters that need to be remembered.