answerWhich of these is not abstract?OptionsThreadListAbstractListNone of the Mentioned

To determine which of the options is not abstract, let's analyze each one:

1. Thread: This is a concrete entity in programming that represents a separate path of execution in a program. It is not an abstract class or concept; it has a direct implementation in various programming languages.

2. AbstractList: This is typically an abstract class provided by collections frameworks (like Java's Collection Framework) that allows for implementing list functionalities without specifying the complete implementation.

3. None of the Mentioned: This option suggests that all other options provided are abstract, which is not the case since one of them is concrete.

Conclusion:

The correct answer to the question "Which of these is not abstract?" is Thread. It is a concrete implementation and not abstract.