How can an unbounded ADT be implemented as an array-based structure?

A) When the array is full, a larger array is allocated and the current array elements are copied to the new array.

B) When the array is full, new items simply overwrite older items in the array.

C) When the array is full, a second array is allocated and the structure contains both arrays.

D) It is not possible to implement an unbounded ADT as an array-based structure.