Best response to 1.d4

Yes, of course not but what is your favorite?

Yes, you could make many different positions

I think the best would be East Indian Defense if they try to Play the Queen's gambit

if not then Dutch Defense would be the best

I usually play the Queen's Gambit Declined: Queen's Knight Variation or the Queen's Gambit Declined: Marshall Defense

Just find an opening repitoire for black. There can be surprising transpositions between e4/d4 openings that make it simple to play. I use Christof Sielecki's KIS for black. This should be appropriate for your level as well.

Against d4, I like playing b6 followed by Bb7 and e6. This can lead to a fun attacking game for me because I have my light-squared bishop staring at the opponent's king if they castle short. I often get to play f5 in these positions too, which gives me some Dutch-like attacking ideas. Overall, a very fun system that takes most d4 players out of theory.

Budapest Defense

Grunfeld defense

d5 (pawn can't advance), queen AND bishop can develop, and opponent would likely respond with e4

Nf6, attacking d4, opponent likely to respond with Bf4 or 5

Kf6, further developing, and guarding

????

what's confusing about this?

1. nf6 does not attack d4
2. Kf6 is always bad and should never happen in the opening
3. opponent will never respond with e4 after d5 in the queens pawn
this guy shouldnt be giving opening advice

I would play Nf6, trying to get into a Sicilian. Otherwise you can go

1. d4 Nf6

2. c4 e6

and then you play d5 or something. This is called the Indian Game.

nf6

nf6 or g6 or the combination of the two.

Kings indian is what I play and if given the chance, ill play the benoni defense which is pretty fun and aggressive

I like to play d5 because if they play queens gambit one of the most popular openings after d5 play the Slav. If they don’t play queens gambit, let’s say Nf3, respond with Nc6.

Anyone asking what is the best response to 1 d4 likely should play 1 ... d5.