Which of the following types of malware can cause a computer's performance to degrade by overwhelming it with tasks?

A botnet is a network of infected computers controlled remotely by an attacker, often used to perform coordinated tasks that can overwhelm systems. When a computer becomes part of a botnet, it may be instructed to execute various tasks—such as sending spam emails, launching distributed denial-of-service (DDoS) attacks, or participating in other malicious activities. This can lead to significant degradation of the computer’s performance, as its resources are redirected to carry out the tasks assigned by the botnet operator.

In contrast, a virus attaches itself to legitimate programs and requires user action to spread, typically causing harm directly to files rather than overwhelming system resources. Adware primarily focuses on delivering unwanted advertisements to users and can slow down a system, but it does not operate through task overload in the same way. Worms are self-replicating malware that spread across networks but generally do not utilize the infected systems' resources for tasks that would degrade performance to the extent a botnet can cause. Thus, the ability of a botnet to launch multiple coordinated tasks makes it the correct answer for causing significant performance degradation.