Unschoolers and like-minded folks!

 My very unsupportive high school teacher father is going to read one  book about unschooling, but only one.  I’ve narrowed it down to 4 titles.  Which one should he read? 

How Children Fail
John Holt
How Children Learn
John Holt
Dumbing Us Down: The Hidden Curriculum of Compulsory Schooling, 10th Anniversary Edition
John Taylor Gatto
Weapons of Mass Instruction: A Schoolteacher’s Journey Through the Dark World of Compulsory Schooling
John Taylor Gatto

Or maybe a different title?
(For a little bit of back story I am 17, and I am only looking for him to have a deeper insight into the flaws of the educational system and the thought process behind unschooling). Thoughts?