CompTIA A+ Certification Exam: Core 2 (#8)

Joe, a customer, calls a technician to report a remote computer is demonstrating erratic behavior while he is working on it. The technician verifies the files and directories. Joe is working on locally cannot be opened in any application, and the computer is running extremely slow. Which of the following is the MOST likely cause of this issue?

Files disappearing
File permission changes
Application crash
Too many startup items