Explanation:

You are calling the Face API to find similar faces from an existing list called employeefaces.
Key facts from the scenario:
The list contains 60,000 images.
In Face API:
faceListId # limited to 1,000 faces.
largeFaceListId # designed for very large lists, up to 1,000,000 faces.
Since employeefaces has 60,000 images, you must use LargeFaceListId, not faceListId.
Parameters in the Request Body
" faceId " : " 18c51a87-3a69-47a8-aedc-a54745f708a1 "
This is the face to search for.
" largeFaceListId " : " employeefaces "
Must use LargeFaceListId because the list has 60,000 images.
" maxNumOfCandidatesReturned " : 1
Limits the number of matches returned.
" mode " : " matchFace "
Two options exist:
" matchFace " # returns the most similar individual faces.
" matchPerson " # groups faces by person.
Since the requirement is find similar faces, use " matchFace " .
Completed Answer
{
" faceId " : " 18c51a87-3a69-47a8-aedc-a54745f708a1 " ,
" largeFaceListId " : " employeefaces " ,
" maxNumOfCandidatesReturned " : 1 ,
" mode " : " matchFace "
}
Correct Values to Drag and Drop
LargeFaceListId # " employeefaces "
matchFace # " mode "
Final Answer:
First blank: LargeFaceListId
Second blank: matchFace
Microsoft References
Face API - Find Similar
Face API - Large Face List operations