The question is asking for two possibilities, it is not asking for two combined configurations. With RAID6 you need 6 total fault domains minimum. We have six hosts, so R6 can be configured, but there will be no rack awareness. You could also build 3 fault domains manually at the rack level. You then have only 3 fault domains and R6 will not be possible in this case. with 3 fault domains you could use only PFTT=1 and Mirroring.

Scroll down to the bottom of this page on Stretched Clusters and Fault Domains: https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan-planning.doc/GUID-1BDC7194-67A7-4E7C-BF3A-3A0A32AEECA9.html

The question is about rack failure, not disk failure. There are three racks and it does not specify where they are located or their proximity to one another. Stretched Clusters require 3 Fault Domains (not 4 or 6 like the two RAID configs). A 2 node config would put the witness on a node in the same rack so that is not the answer. The only answers left are B and C. This gives us Rack Awareness with one Fault Domain on each of the three racks.

C & D. If you use RAID-5/FTT=1 and you loose a rack, you loose objects too. You could create 3 FD (2 host per RACK) and RAID 1. The another option is use RAID-6/FTT=2, you can loose 2 host (a complete rack).

PFTT must be 2 and 6 fault domains from each host. CD is the correct answer You can configure RAID 5 on all-flash clusters with four or more fault domains. You can configure RAID 5 or RAID 6 on all-flash clusters with six or more fault domains.

The rule is 2*n+1. FNTT=2 is not possible on 3 Fault Domains

if we will take 100GB vmdk on raid 6 we will use 150 GB. on raid 5 we will use 133GB. correct answer is a,c

Answer is C and D 3 fault domain with raid 6 FTT2 can achieve this

C&D. Question states "maximizing resources". Raid6 can sustain 2 failures and will protect against rack failure if each host is fault domain.

RAID-6 FTT2 requires 6 hosts to work. Since the admin has 6 hosts available the best way to protect for a rack failure is to set 3 fault domains with 2 hosts each and RAID-6 FTT-2. So C and D

Should be A&C

If the administrator puts 2 hosts in each rack, and one rack fails, two hosts will be offline. So in my opinion he should configure RAID6 FTT=2 and define fault domains. So for me it should be C and D

have those 6 hosts and every host is a FD. The loss of a single rack equals 2 host failures and this is the max RAID-6 can protect us against. https://www.softwaredefinedblog.com/fault-domain-examples-in-vsan/ Example3

protect against a rack failure So,A&C

Should be A&C - we do this every day.