The correct answer is C. .net.
A thread is a single sequential flow of control within a process. In .NET, an object of type Thread in the namespace System.Threading represents and controls one thread.
Option A, .py, is the extension for Python files. Python is a high-level, general-purpose programming language. It is used for web development, data science, machine learning, and artificial intelligence.
Option B, .sap, is the extension for SAP files. SAP is a software company that provides enterprise resource planning (ERP) software. ERP software is used to manage a company’s finances, operations, and human resources.
Option D, .exe, is the extension for executable files. Executable files are programs that can be run on a computer.
I hope this helps!