Solution

The correct answer is option 4.

Key Points

Statement A: TRUE:  

Post Office Protocol (POP) is a type of computer networking and Internet standard protocol that has two modes, Delete mode and keep mode.

Statement B: TRUE:  

In Delete mode, the mail is deleted from the mailbox after each retrieval.

and hence statement C is FALSE

Statement E: TRUE:  

In keep mode, mail remains in a mailbox after retrieval.

and statement D is FALSE

Therefore the correct answer is (A), (B), and (E) only.

Hint

Delete Mode ( delete after reading ).

Keep Mode ( stores even after reading ).