Please explain the logic and explanation because i am not able to understand anything and i am crying so much.

Transactions T1 caused a deadlock. To change the system to a stable state you would :

A. Deadlock

B. Undo

C. Savepoint

D. Rollback

Data Structures and Algorithms :

What Data Structure is more suitable for Arithmetic Expression Evaluation?

A. Queue

B. Stack

C. Graph

D. Tree

Trouble Shooting :

You log in to a Linux system and you see that disk utilization is at 99%, what are the next steps? (more than one correct answer)

A. Use free command to check the usage

B. Use df and du commands to check the usage

C. Check load Average on the system

D. Use find command to find and clear space

E. Use lsof to see if any services are creating a lot of files and confirm if you can clear the same.

F. All the above.

Linux/Unix :

What is the size of the files under /proc directory?

A. 100 Bytes

B. 0 Bytes

C. Depends on the Content

D. 100 MB

Web Technologies :

Which HTTP status code is usually returned when the resource is cached?

A. 401

B. 503

C. 304

D. 200