I would say A because it was talking about something in the present but what they were talking about was in past. so I would think A
        
             
        
        
        
Answer:
"backdoor" is the correct answer for the above question
Explanation:
- The backdoor is a type of attack which is done by the type of backdoor programs to remotely access the computers without the authorization of the user of the computer.
- It is inserted on the computer with the help of the internet and accessed the computer without using authorization techniques.
- The above question asked about the virus which is used to access the computer without the permission of the right use of the system. Hence the answer is backdoor which is defined above.