Oracle Exam 1Z0-105 Topic 11 Question 7 Discussion

You have a mounted mirrored btrfs file system in RAID-1 on /btrfs:

# btrfs filesystem show

Label: 'Btrfs' uuid: 7bfe3239-47ee-442b-b9f8-49f88b6b1be4

Total devices 2 FS bytes used 250.46MB

devid 2 size 4.88GB used 1.54GB path /dev/sdd

devid 1 size 4.88GB used 1.54GB path /dev/sdc

You found an error on one device:

#btrfs scrub start --B --d --r /btrfs

scrub device /dev/sdc (id 1) done

scrub started at Wed Aug 21 15:33:05 2013 and finished after 6 seconds

total bytes scrubbed: 250.34MB with 0 errors

scrub device /dev/sdd (id2) done

scrub started at Wed Aug 21 15:33:05 2013 and finished after 6 seconds

total bytes scrubbed: 250.39MB with 26 errors

error details: read=13 csum=13

corrected errors: 13, uncorrectable errors: 0, unverified errors: 0

Which statements repairs the corrupted blocks?