You are right and I will change the responses to fit.
A more general question is how "hard" the game is supposed to be. If a player does not read the the text there will be a lot of instances where you will not be able to progress as it will require the player to ask a specific character about a specific subject that is hinted at in the text. If a case as simple as this where the NPC says what you have to say back, can cause issues, then there will be a lot of things that I would not even dream about trying to implement in fear of the player getting stuck and giving up.
The game has no time limit and you cannot fail the main story. The challenges I have planned are small compared to other adventure, rpg or puzzle games but still requires some player awareness and problem solving. A lot of games require a large amount of trial and error and that is not something I am a fan of. The only reason to load a save is to continue where you left off.
So what difficulty setting should I make the game for?
Visual novel - No puzzles, just events happening at the player. 0% of players should need a walkthrough.
Adventure - Some puzzles, players have to follow hints and solve problems on their own. 10-50% of the players might need a walkthrough once in a while.
Oldschool adventure - Hard puzzles that might even require outside knowledge to solve. 50-99% of the players might need a walkthrough and some might even follow it all the way through.
The goal was to place it somewhere in relaxed adventure. But if players would rather have an interactive story then I can do that as well.