The OmniScript element BlkContacts is configured as a Repeat Block. A Repeat Block is designed to iterate over a list of items and requires its input data to be a JSON array. The name of the JSON node containing the array must match the name of the Repeat Block element. Option A provides the correct structure: a root JSON object with a key named BlkContacts, whose value is an array of objects ([...]). Each object inside the array contains the key-value pairs that directly map to the input elements (FirstName, LastName, etc.) within the BlkContacts block, enabling the OmniScript to populate the fields correctly.

B: The BlkContacts node is a single JSON object, not an array. A Repeat Block cannot iterate over a single object and requires an array structure.

C: This JSON structure is a flat object and completely lacks the required BlkContacts parent node, so the OmniScript cannot find the data for the block.

D: The root of the JSON is an array, and the BlkContacts node is nested inside it. The OmniScript expects a root object with a BlkContacts array, not this nested structure.

1. Salesforce Help

OmniStudio Documentation

"Pass Data to an OmniScript": This document explicitly states

"To pass a list of items into an OmniScript

the JSON must have a node that is an array... The OmniScript element that receives the data must have the same name as the array node." This directly validates that a Repeat Block named BlkContacts requires a JSON structure of {"BlkContacts": [...]}.

2. Salesforce Help

OmniStudio Documentation

"OmniScript Block Element": In the properties table for the Block element

the "Repeat" checkbox description clarifies that enabling it "repeats the Block for each item in an array." This confirms the fundamental requirement of an array for the Repeat Block functionality.

3. Trailhead

OmniStudio Documentation

"OmniScript Data JSON": This module provides examples of the data structure OmniScripts expect. For repeatable blocks

the examples consistently show a named node that contains an array of objects

matching the structure in Option A. For instance

a repeatable block named Account would expect {"Account": [{"Name": "Acme"}

{"Name": "Global"}]}.