A technician is replacing a processor in a workstation. After installation, the workstation starts up and immediately shuts down; the technician tries to start the workstation several more times and gets the same result. Which of the following is the cause of this issue?（）

A. The workstation is not plugged in.
B. The thermal paste was not applied.
C. The memory was not installed properly.
D. The L2 cache was not cleared.