You need to design a multi-region disaster recovery solution. Which strategy involves maintaining a fully operational secondary environment?

Correct answer: Hot standby

Option B is correct because a hot standby disaster recovery strategy maintains a fully operational, continuously synchronized secondary environment that can accept traffic immediately with near-zero RTO, making it the most available and most expensive DR tier. Option A is wrong because warm standby keeps a scaled-down but running copy of the environment that requires scaling up before it can handle full production load, resulting in some recovery time. Option C is wrong because cold standby involves backing up data and storing configurations but not running infrastructure, requiring significant provisioning time before recovery can begin. Option D is wrong because having no backup strategy provides no disaster recovery capability at all and is not an accepted DR pattern.