[A]
Which resides in the memory till the end of the program
[B]
Which is globally accessible by all functions
[C]
Which is declared outside the body of any function
[D]
All of the above
Answer & Explanation
Option: [D]
An external variable is the one which is created outside the body of the function, i.e. within the source code file. The scope of the external variable is till the end of the program.