Practice question for security plus I think is wrong. Integrity vs availabilty

So there is the following question on a practice test:

Which service are you addressing by installing a RAID array and load balancer?

A. Confidentiality B. Availability C. Accountability D. Integrity

The correct answer according to practice test is “Integrity”.

Can someone explain this and why it would not be Availability? Not understanding how availability wouldn’t be the correct choice.