incremental backup query

 I have two optons of incremental backups.

1.which one is better A or B?

A.  backup to disk first then to tape

RUN

{

  RECOVER COPY OF DATABASE 

    WITH TAG 'INCRE_UPDATE';

  BACKUP

    INCREMENTAL LEVEL 1

    FOR RECOVER OF COPY WITH TAG 'INCRE_UPDATE'

    DATABASE;

}

what happens if level 0 is corrupted, i need to take from tape.Is it my correct understanding?

B. -- Eevery sunday  , first backup to disk then to tape.

run {

configure channel device type disk format 'D:\backups\testdb\%d_%T_s%s_%U';

CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO 'D:\backups\testdb\%d_%F';