An attempt is an effort to complete a stage within a challenge. There are 3 possible stages:
Select Vulnerability Category
Select a vulnerability category and press 'Submit'
Select the Vulnerable code blocks and press 'Submit'
Click 'View Solutions'
Select one of the solutions from the drop-down menu on the right-hand side and click 'Accept'
Hot Tip: You can compare two solutions by using the drop-down menu to the left-hand side. Refer to the screenshot below