Your database is in shutdown state. What will happend if you issue next command: SQL> startup

Stopping at the instance-started phase requires the STARTUP NOMOUNT clause; a plain STARTUP continues past NOMOUNT automatically.

Stopping at the MOUNT stage requires the STARTUP MOUNT clause; without it the database continues past mount to the OPEN phase.

The sequence is always NOMOUNT then MOUNT then OPEN - the database must be mounted before it can be opened, so the order described in C is impossible.

The STARTUP command without additional clauses progresses through three sequential phases: first the instance is started by allocating the SGA and launching background processes (NOMOUNT), then the control file is read and the database is mounted, and finally the datafiles and online redo logs are verified and opened, making the database fully accessible to users.