TestOut Linux Pro Practice Test 2025 – All-in-One Guide to Master Your Certification!

To format a partition with the ext4 file system, the command must specify the `mkfs` utility, the `-t` option for defining the type of file system, and the target partition. The use of `-t ext4` clearly indicates the intention to format the partition with the ext4 file system, which is known for its features like journaling, improved performance, and support for larger files and file systems when compared to older file systems such as ext3.

In the selected answer, the command is structured correctly with `mkfs -t ext4`, and it targets the correct partition, indicated as `/dev/sdb2`. This effectively prepares the specified partition for use with the ext4 file system.

The other options present variations that either use the wrong file system type or target a different partition, which would not result in formatting it as ext4. For instance, using `ntfs` or `ext3` does not meet the requirement of formatting the partition as ext4, making those options unsuitable for this task.