What is the difference between std::mutex and std::recursive_mutex in C++ multi-threading?

A. A process that allows parallel execution of tasks B. A process that allows a single thread to execute C. A process that allows multiple processes to execute concurrently D. A process that allows multiple threads to execute concurrently

A. <mutex> B. <condition_variable> C. <thread> D. <atomic>

A. 2 B. Depends on the hardware and operating system C. 4 D. 8

A. To define thread-specific data B. To manage thread priorities C. To create and manage threads D. To synchronize access to shared resources