Set the stanza to have a server value equal to a comma-separated list of IP addresses and indexer ports for each of the indexers in the environment. This is explained in the Splunk documentation1, which states:
To enable automatic load balancing, set the stanza to have a server value equal to a comma-separated list of IP addresses and indexer ports for each of the indexers in the environment. For example:
[tcpout] server=10.1.1.1:9997,10.1.1.2:9997,10.1.1.3:9997
The forwarder then distributes data across all of the indexers in the list.

Per the provided reference URL https://docs.splunk.com/Documentation/Splunk/7.3.1/Admin/User-seedconf
"To set the default username and password, place user-seed.conf in $SPLUNK_HOME/etc/system/local. You must restart Splunk to enable configurations. If the $SPLUNK_HOME/etc/passwd file is present, the settings in this file (user-seed.conf) are not used."

Hot/warm/cold/thawed bucket types are searchable. Frozen isn't searchable because its either deleted at that state or archived.

https://docs.splunk.com/Documentation/Splunk/latest/Admin/Outputsconf
# Compression
#
# This example sends compressed events to the remote indexer.
# NOTE: Compression can be enabled TCP or SSL outputs only.
# The receiver input port should also have compression enabled.
[tcpout]
server = splunkServer.example.com:4433
compressed = true

Reference:
The fishbucket is a directory that stores information about the files that have been monitored and indexed by Splunk. The fishbucket helps Splunk avoid indexing duplicate data by keeping track of file signatures and offsets. To reset the fishbucket for one source, the command splunk cmd btprobe can be used with the -reset option and the name of the source file. Therefore, option C is the correct answer. Reference: Splunk Enterprise Certified Admin | Splunk, [Use btprobe to troubleshoot file monitoring - Splunk Documentation]