FROM BOL: copy and pasted

STOPAT = date_time | @date_time_var

Specifies that the database be restored to the state it was in as of the specified date and time. If a variable is used for STOPAT, the variable must be varchar, char, smalldatetime, or datetime data type. Only transaction log records written before the specified date and time are applied to the database.

Note  If you specify a STOPAT time that is beyond the end of the RESTORE LOG operation, the database is left in an unrecovered state, just as if RESTORE LOG had been run with NORECOVERY.

Therefor this answer "The full backup will be restored and the transaction log will be applied to 10PM. " is correct assuming the user uses TSQL to restore the database.