Fianchetto formations (like the King's Indian) are OK against the London.
That would be my choice.
Should I learn the Kings Indian Defense, Nimzo, or The Benoni??
Sort:
ok in order:
a) you can not avoid the London as black. unless you play 1.d4,c5. but now you have committed to a Benoni game of some sort. or if white plays 2.e4 you are in an open Sicilian.
b) The Benoni games are all different from each other depending upon whether you play b5, e5, or e6.
c) the Nimzo is good but you will need to learn the Bogo Indian as well if white plays Nf3.
d) the KID is also good but you will have to learn a bunch of theory and be good at defending an open king.
My opinion only: KID is an opening where you learn a lot that improves your game in lots of other openings. Benoni is an exciting defense but IMO its middle game intersects KID so I'd want to learn some basics of KID first.
I dont play the Nimzo but my impressions is that it is an opening for a lifetime. My untutored impression is that its MG intersects QGD MGs, especially if white avoids it with Nf3.
FWIW, There are lots of KID & Nimzo games in Zurich 1955.
The Nimzovich Indian Defense is the more sound of the three.
King's Indian Defense and Benoni Defense are dubious in classical games at top grandmaster level. At lower levels and faster time controls it does not matter.
I hate playing against those London and Queens Gambit players (even though I know basic theory and play it often with white.) I have chosen three openings after Nf6, The Benoni, Nimzo, and The Kings Indian Defense. They are all pretty similar in their ways and variations, and can even transpose to one another. But I can't decide which one should I add to my repertoire (and study) after d4, for black.