Final answer:
Usurpation occurs when hackers replace legitimate computer programs with unauthorized ones to disrupt operations, leading to serious consequences like identity theft and national security threats.
Step-by-step explanation:
The correct answer to the question is D: Usurpation. This term refers to the act when computer criminals, often called hackers, invade a computer system and replace legitimate programs with unauthorized ones. These illicit programs could then shut down or interfere with the operations of legit applications, causing disruptions and possibly leading to theft of data or identity. In the modern world, such activities by hackers lead to significant issues such as identity theft, financial fraud, compromising national security, power grid shutdowns, and even interference in elections. The harm from data breaches and the chaos they induce is substantial, both financially and in terms of public trust.