Which of the following statements about the UNIX file system is NOT correct?

Explanation

The super block genuinely records the i-node count, the disk-block count, and the head of the free-block list (statement 1, true); an i-node genuinely holds ownership/permission accounting data plus the direct and indirect pointers needed to find every data block of a file (statement 2, true); and file/directory contents are indeed stored in data blocks referenced from their i-node (statement 4, true). The i-node's size, however, is not a universal fixed constant — it is implementation-defined and has varied across UNIX versions (e.g. 64 bytes in early Version 7 UNIX, larger in many System V and modern variants), so asserting a single fixed size of 256 bytes is the incorrect statement, option (iii).