Checking the Send Only Additional Input checkbox allows the Remote Action element to send only the key
/value pairs specified in Additional input to the Apex method. The Additional input should have the same keys as the method parameters, and the values should be set to {{InputData.node}} for each node. For example, AccountId: {{InputData.AccountId}} and ProductId: {{InputData.Details.Products}}.

From the OmniStudio OmniScript Documentation:
* A Repeat Block (like BlkContacts) expects an array of objects.
* Each item in the array must contain fields that exactly match the UI elements inside the block.
* The parent JSON must include any top-level values used by individual input fields (like AccountName, AccountPhone).
Why the Other Options Are Incorrect:
* B. Uses Contacts instead of BlkContacts, and is incomplete/malformed.
* C. Repeats keys at the same level instead of using an array structure. This causes the data to overwrite and fail to display properly.
* D. Uses incorrect keys like "Name" and "Phone" instead of expected "ContactName" and
"ContactPhone", breaking field binding.
Reference:
Salesforce OmniStudio Developer Guide # OmniScript Repeat Blocks & Data JSON Structure DataRaptor Extract Output # Mapping JSON for OmniScripts

According to the DataRaptor Load Overview page, a Linked Mapping is used to "create or update multiple records in different objects that are related by lookup fields".

The element name for the missing data must match the JSON node key in the Integration Procedure Response, otherwise the data will not be mapped correctly. The JSON sent from the Integration Procedure Action must match one of the Original Input for the Integration Procedure, otherwise the Integration Procedure will not execute properly. The Integration Procedure Preview Input Parameters and the Response JSON Path have no effect on displaying data in OmniScript.

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)".