According to the DataRaptor Transform Overview page, a DataRaptor Transform can be used to "pre-populate data in PDFs used by OmniScripts".

According to the OmniScript Action Elements page, a DataRaptor Extract Action can be used to "get data from one or more Salesforce records" and an HTTP Action can be used to "get, save, or delete data through a web application programming interface (API)".

Setting the Timeout property on the HTTP Action in the Integration Procedure allows the developer to specify how long to wait for a response from the external system before timing out. Checking the Chain on Step Check on the HTTP Action in the Integration Procedure allows the developer to chain multiple HTTP Actions together and execute them sequentially. Configuring a Remote action with timeout settings of 120000 is not necessary, as it is already done by default in OmniStudio. Checking the Chainable checkbox on the integration procedure Action in the OmniScript has no effect on calling an external system.

The Node field for the parent FlexCard should be set to {Records}, which is an array of all the records retrieved by the parent FlexCard data source. This will allow the child FlexCard to access the records and display them in a DataTable.

The correct answer is D. Data Mapper Turbo Extract, based on best practices in the official OmniStudio documentation.
From the OmniStudio Developer Guide # DataRaptors # Turbo Extract:
* DataRaptor Turbo Extract is a lightweight, high-performance extract designed specifically for retrieving data from a single Salesforce object, where no data transformation or complex joins are required.
* It is recommended over DataRaptor Extract for performance reasons when only one object and minimal transformation is needed.
Why not the others?
* A. DataRaptor Load is used for writing data to Salesforce, not retrieving.
* B. DataRaptor Transform is used when you need to transform data, not simply extract it.
* C. DataRaptor Extract can be used, but Turbo Extract is preferred for the use case of single object, no transformation - per best practices.
:
Salesforce OmniStudio Developer Guide # DataRaptor Turbo Extract Best Practices OmniStudio Certification Study Guide # "When to use Turbo Extract"