Which of the following correctly describes the meaning of ‘namespace'feature in C++?

• A. a. Namespaces refer to the memory space allocated for names used in a program
• B. b. Namespaces refer to space between teh names in a program
• C. c. Namespaces refer to space between the names in a program
• D. d. namespaces provide facilities for organizing the names in a program to avoid name clashes