Northern Trail Outfitters (NTO) wants to bring data from across all parts of their Salesforce...

C is correct because Marketing Cloud Connect uses the SOAP API to integrate multiple business units in Marketing Cloud with Salesforce core orgs. The SOAP API enables data synchronization, triggered sends, journey builder integrations, and tracking data.

A is incorrect because the Tooling API is used to create and modify metadata in Salesforce core orgs, such as custom objects, fields, workflows, etc. It is not used for Marketing Cloud Connect integration.

B is incorrect because the REST API is used to access resources in Marketing Cloud, such as contacts, content, campaigns, etc. It is not used for Marketing Cloud Connect integration.

D is incorrect because the Streaming API is used to receive notifications of data changes in Salesforce core orgs, such as record updates, deletes, etc. It is not used for Marketing Cloud Connect integration.

References:

: https://developer.salesforce.com/docs/atlas.en-us.mc-apis.meta/mc-apis/index-api.htm

: https://developer.salesforce.com/docs/atlas.en-us.api_tooling.meta/api_tooling/intro_api_tooling.htm

: https://developer.salesforce.com/docs/atlas.en-us.mc-apis.meta/mc-apis/index-api.htm

: https://developer.salesforce.com/docs/atlas.en-us.api_streaming.meta/api_streaming/intro_stream.htm