The macro va_arg is used to extract an argument from the fixed micro argument list and 

advance the pointer to the next argument.

It is necessary to call the macro va_end if va_start is called in the function.

Can the fixed arguments passed to the function that accepts variable argument list, 

occur at the end?

Can we write a function that takes a variable argument list and passes the list to another function?

Is it necessary that in a function which accepts variable argument list there should be 

at least be one fixed argument?

While defining a variable argument list function we drop the ellipsis(...)?

va_list is an array that holds information needed by va_arg and va_end

A function that receives variable number of arguments should use va_arg() to extract the 

last argument from the variable argument list.

The macro va_start is used to initialise a pointer to the beginning of the list of fixed arguments.

Can we pass a variable argument list to a function at run-time?