Which of the following should be checked next in order to diagnose this problem?

The directory /home is on an ext2 file system. The owner is able to delete other files in the directory, but all attempts by the owner of /home/owner/A to delete the one file result in the output:

bash:

A.
Permission denied
Given the file listing:
-rw-r–r– 1 owner owner 5 Jun 13 12:14 A
Which of the following should be checked next in order to diagnose this problem?

B.
mkfs

C.
dmesg

D.
lsattr /home/owner/A

E.
rm -r /home/owner