You are tasked with developing an application that requires the use of Oracle Cloud Infrastructure (OCI) APIs to POST messages to a stream in the OCI Streaming service. Which statement is incorrect? (Choose the best answer.) 

Answer options:

A. The request must include an authorization signing string including (but not limited to) x-content-sha256, content-type, and content-length headers.
B. The Content-Type header must be set to application/json
C. An HTTP 401 will be returned if the client`s clock is skewed more than 5 minutes from the server`s.
D. The request does not require an Authorization header.

D

Reference: https://docs.cloud.oracle.com/en-us/iaas/Content/API/Concepts/signingrequests.htm