What is the most difficult US military school?

Hands down. They all are, but one that stands in my mind is BUDS/UDT

Cls

Air Intercept Controller... Not physically hard at all, I started day one in a room of 20 by taking a written exam. Pass with a minimum score or go home. 8 of us got in the class, 4 of us graduated.

Language Facilitator, after hard nights of drinking past our per diem, crawl back to the hotel room....!

Bradley Master Gunner school. Mentally exhausting...

Flight school.

Air Assault School - "10 toughest days in the US Army"

Armed Forces School of Music

Of the schools I attended. NATO LRRP school in Germany was probably the toughest. There was only one test, no retest, you passed or failed. Next was 12B BNCOC. I was never good at math, but by the time they got done with me I could do demo formulas with a pen and paper. 11B ANCOC was a tough one as well.

Is that a picture of morning prayers at a Jesuit seminary?