Heap-Only Tuple (HOT) updates in PostgreSQL optimize write performance by:

1. A Writing update payloads directly to the Write-Ahead Log (WAL) while skipping the Heap entirely to ensure absolute write-throughput.
2. B Utilizing an in-memory buffer pool to merge multiple contiguous updates into a single physical disk write during off-peak hours.
3. C Silently disabling all Foreign Key and Check Constraints during high-frequency update bursts to minimize the internal processing overhead.
4. D Creating a new version of the row within the same physical disk page and using a local pointer chain to bypass the need for standard index updates.