Solved: Which former U.S. Defense Secretary, on November 28, 2021, sued to stop the DoD from blocking material for use in his memoir?

Question:  Which former U.S. Defense Secretary, on November 28, 2021, sued to stop the DoD from blocking material for use in his memoir?

Chuck Hagel
Ash Carter
James Mattis
Mark Esper
Christopher Miller

The correct answer is Mark Esper.