You are at the top of the hierarchy and must configure OSPF on interface so-0/0/0 unit 100. Which two achieve this result? (Choose two.)

`set protocols` is an incomplete command and does not specify what protocols to configure or how, so it cannot achieve the desired result.

The `set protocols ospf area 0 interface so-0/0/0.100` command directly creates or modifies the OSPF configuration for the specified interface within area 0 from the top-level configuration mode. This is a common method for direct configuration using the `set` command.

`edit protocols ospf interface so-0/0/0.100` attempts to directly `edit` an interface within OSPF, but `interface` is not a direct child of `ospf` at the top level for `edit` to work this way; it should be under `area`.

The `edit protocols ospf area 0` command changes the current configuration hierarchy level to `[edit protocols ospf area 0]`. From this new level, you can then issue further commands to configure interfaces specific to area 0, making it an efficient way to structure subsequent OSPF interface configurations.