You need to extend the model-driven app by using a JavaScript client script. The script should retrieve multiple records from the Dataverse contact table using Web API. 
What Client API object would you use for data retrieval?

Answer options:

A.Xml.WebAPI
B.FetchXML
C.executionContext
D.Xrm.WebAPI
E.formContext

Correct Answer: D 
Power Apps provides the Client API model for model-driven apps for users to implement in their business logic. The Client API model includes objects and methods that developers can access using Javascript code. 
There are four root objects of the Client API model: executionContext — this is an execution object of the model-driven app. It gives access to the context of the forms and grids.
formContext — provides access to the form object using the executionContext.
gridContext — provides access to the grid (subgrid) on a form.
Xrm — provides access to the global object for operations that do not directly impact UI and data in forms, grids, controls.
The Xrm.WebAPI object uses Web API for the Dataverse data access. It has two properties: online and offline.A list of methods includes the record operations, a retrieval of the multiple records, and execution of the single or multiple actions, functions, or CRUD operations. 
To retrieve multiple records from the Dataverse contact table, you use the retrieveMultipleRecords method, like in the following statement: 

All other options are incorrect. 
For more information about model-driven app’s Client API scripts using WebAPI, please visit the below URLs: 

https://docs.microsoft.com/en-us/powerapps/developer/data-platform/webapi/get-started-web-api-client-side-javascript
https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/reference/xrm-webapi
https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/understand-clientapi-object-model