A developer needs to configure a Data Mapper to retrieve data from a single object.

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"