In your cognitive search solution, you plan to use search-as-you-type feature using the API services offered in Azure. It would enhance user experience and productivity by finishing a phrase or matching the documents. Review the API services in the answer choice below and select the one that returns the document id in order to fetch the document for the search-as-you-type feature.

Answer options:

A.Search API
B.Autocomplete API
C.Suggestions API
D.Gremlin API

Correct Answer: C
Option A is incorrect because Search API is used for cognitive search. However for search-as-you-type, you need to use the Autocomplete or Suggestions API.
Option B is incorrect because the Autocomplete API, while supports search-as-you-type feature, does not provide the document id to fetch the document.
Option C is correct because Suggestions API returns terms and the document id. This way you can fetch the search documents.
Option D is incorrect because the Gremlin API is used to index cognitive search data in Cosmos DB.Reference:
To learn more about Cognitive search autocomplete and suggestions, use the link given below: 

https://docs.microsoft.com/en-us/azure/search/search-add-autocomplete-suggestions