For the Exchange VM experiencing I/O performance issues, the recommended storage optimization change is Option A, "No data reduction." Exchange, as an application, is highly sensitive to latency and typically does not benefit significantly from data reduction technologies like deduplication or compression, which can introduce additional processing overhead and potentially worsen performance issues.

By configuring the container for Exchange with no data reduction, the system maximizes I/O performance by eliminating any additional processing that could delay data access. This setup ensures that Exchange has the fastest possible access to its data, which is crucial for its performance.

References:This recommendation aligns with best practices for Exchange storage on Nutanix, as detailed in the Nutanix best practices guide for deploying Microsoft Exchange, where it advises against using data reduction features for databases requiring high I/O throughput.