An Oracle instance is executing in a nondistributed configuration. The instance fails because of an operating system failure. Which background process would perform the instance recovery when the atabase is reopened ?

The System Monitor (SMON) background process is responsible for performing instance recovery when a crashed database is reopened. It applies redo log entries (roll forward) and discards uncommitted changes (roll back). PMON cleans up failed user processes, RECO resolves distributed transactions, and CKPT updates file headers during checkpoints.