“What do they teach you in pre-K?”/“The first 10 letters.”

“Pre-K” means “pre-kindergarten,” but a riddle was posted on Reddit—3amjokes on November 6, 2018:
 
Q: What do they teach you in pre-K?
A: The first 10 letters.
 
 
Reddit—3amjokes
What do they teach you in pre-K? self.3amjokes
Submitted November 6, 2018 by 0-o-0-o-0-o-0
The first 10 letters
COMMENTS
JerLoser
What?
 
0-o-0-o-0-o-0
A b c d e f g h I j - K
 
Twitter
3AM
@3AM_Jokes
What do they teach you in pre-K?... The first 10 letters
7:42 PM - 6 Nov 2018

Education/Schools