The 401 Unauthorized status code indicates that the request lacks valid authentication credentials. When using OAuth2 for authenticating with the Cisco Webex API, the correct approach is to include a Bearer token in the Authorization header.

Option A:header = {"Authorization": "Bearer YOUR_TOKEN"}

This option correctly formats the Authorization header, which is necessary for the Webex API to authenticate the request. The Bearer token is a type of token used by OAuth2 to access protected resources.

Authorization Header: The header must contain the key "Authorization" with the value formatted as "Bearer YOUR_TOKEN".

Bearer Token: The Bearer keyword followed by a space and the token itself is the correct way to pass the OAuth2 token in the header.

Other Options:Option B:

Incorrect because it uses "Authentication" instead of "Authorization".

Option C:

Incorrect because it combines Authentication and Bearer incorrectly without a space.

Option D:

Incorrect for the same reason as Option C.