O Linux oferece suporte para vários sistemas de arquivos, c...

a) tem suporte para arquivos de até 26 Terabytes de tamanho.
ERRADO, pois o suporte é até 16 Terabytes (2^40) bytes.

b) implementa o recurso de journaling, um sistema anti-falhas que impede que arquivos sejam perdidos.
ERRADO, pois, embora o ext4 implemente o journaling, este não impede que arquivos sejam perdidos; ele apenas oferece uma melhor recuperação quanto a arquivos corrompidos.

c) permite que os arquivos sejam acessados em modo de leitura por usuários do sistema de arquivos NTFS, por meio de utilitário específico.
CERTO,

d) é incompatível com o Ext3
ERRADO, porque é compatível com o Ext3.

ext4 is backward-compatible with ext3 and ext2, making it possible to mount ext3 and ext2 as ext4. This will slightly improve performance, because certain new features of the ext4 implementation can also be used with ext3 and ext2, such as the new block allocation algorithm, without affecting the on-disk format.

https://en.wikipedia.org/wiki/Ext4

The ext4 file system is a scalable extension of the ext3 file system. With Red Hat Enterprise Linux 7, it can support a maximum individual file size of 16 terabytes, and file systems to a maximum of 50 terabytes, unlike Red Hat Enterprise Linux 6 which only supported file systems up to 16 terabytes. It also supports an unlimited number of sub-directories (the ext3 file system only supports up to 32,000), though once the link count exceeds 65,000 it resets to 1 and is no longer increased. The bigalloc feature is not currently supported.

The ext4 file system uses extents (as opposed to the traditional block mapping scheme used by ext2 and ext3), which improves performance when using large files and reduces metadata overhead for large files. In addition, ext4 also labels unallocated block groups and inode table sections accordingly, which allows them to be skipped during a file system check. This makes for quicker file system checks, which becomes more beneficial as the file system grows in size.

https://access.redhat.com/documentation/de-de/red_hat_enterprise_linux/7/html/storage_administration_guide/ch-ext4