Reference: https://docs.splunk.com/Documentation/Splunk/8.0.3/Knowledge/FXSelectMethodstep
https://community.splunk.com/t5/Splunk-Search/Field-Extraction-Separate-on-Colon/m-p/29751 The Field Extractor (FX) is a tool that helps you extract fields from your data using delimiters or regular expressions. Delimiters are characters or strings that separate fields in your data. Some of the delimiters that will work with FX are:
Tabs: horizontal spaces that align text in columns.
Pipes: vertical bars that often indicate logical OR operations.
Spaces: blank characters that separate words or symbols.
Therefore, the delimiters A, B, and D will work with FX.

After manually editing a regular expression (regex) that was created using the Field Extractor (FX) UI, it is no longer possible to edit the field extraction in the FX UI. The FX UI is a tool that helps you extract fields from your data using delimiters or regular expressions. The FX UI can generate a regex for you based on your selection of sample values or you can enter your own regex in the FX UI. However, if you edit the regex manually in the props.conf file, the FX UI will not be able to recognize the changes and will not let you edit the field extraction in the FX UI anymore. You will have to use the props.conf file to make any further changes to the field extraction. Changes made manually cannot be reverted in the FX UI, as the FX UI does not keep track of the changes made in the props.conf file. It is possible to manually edit a regex that was created using the FX UI, as long as you do it in the props.conf file.
Therefore, only statement B is true about manually editing a regex.

Arguments are defined within the macro search string by using dollar signs on either side of the argument name, such as arg1 or fragment.
References
Search macro examples
Define search macros in Settings
Use search macros in searches

This is because event types are added to events as a field named eventtype, and you can use this field as a search term to find events that match a specific event type. For example, eventtype=successful_purchases returns all events that have been categorized as successful purchases by the event type definition. The other options are incorrect because they either use a different field name (tag), a different syntax (Event Type:: or event type-), or have a typo (success ful_purchases). You can learn more about how to use event types in searches from the Splunk documentation1.

The maxspan option in the transaction command limits the maximum time span of the transaction to the specified duration, in this case, 5 minutes. This ensures that only events within that time window are grouped into one transaction.
Reference:
Splunk Power User Study Guide, Transaction Command
Splunk Docs: transaction Command
"maxspan sets the maximum time span allowed for transactions."