Where do most attacks to software come from?

One of your customers reports that she walked away from her laptop for 30 minutes. When she returned, the display was very dim. She increased the brigthness setting and moved the mouse but to no effect. What should you do first?

a. Replace the LCD screen. b. Check the operating system for corruption. c. Connect an external monitor to verify that video card works. d. check wheter the laptop is now on battery power.

A technique in which one system models the behavior of another system is called ____.

A. imitation B. recursion C. simulation D. stimulation