Indexed/grouped allocation (of disk blocks to a file) is useful because:
(A) It supports both sequential and direct access.
(B) The entire data block is available for data (no pointers embedded in it).
(C) It does not require a lot of space for keeping pointers.
(D) It has no external fragmentation.

1. A(A) (A) only
2. B(B) (B) and (C) only
3. C(C) (B) only
4. D(D) (A), (B) and (D) only

Pick an option to check yourself, or open the answer below.