What is the biggest vulnerability to computer information security?

The correct answer is option D
The biggest vulnerability to computer information security is the end user. Unlike applications that can be patched or systems that can be hardened, end users through unawareness and carelessness can expose IT sources to security threats. For example, a financial fraud may leverage on the end user ignorance to gain access to the organization IT infrastructures.

With the increase in cybercrimes, it is important to fully educate employees about security threats and protection against security vulnerability. They should be encouraged to be vigilant at all times and inform them on what is classified as sensitive data.