How can artificial intelligence response?

I think you need two things in your project:
1. Getting input and responding to it using AI, for this you try searching AI Chat Bot on google or this article Building an AI Chatbot using a Regular Expression Engine[^]
2. You might also need to implement speech input and output, for this you can try out these articles[^] or this article.[^]

AI is a huge field with many very different topics. Creating an AI within any of these fields from scratch is a huge topic.

Quote:

it is possible that artificial intelligence can response on what user saying?

Obviously, yes: Just look at (or listen to) bots like Siri, Alexa, etc.. However, it took hundreds or even thousands of developers to create these systems, decades of experience went into it, and thousands of terabytes of data were used to train these systems until they were able to analyze speech reliably and respond to it in a meaningful way. This is lightyears beyond the scope of a simple thesis.

If you really want to investigate this topic from scratch, you might want to learn and experiment with the functional programming language, PROLOG: it has a very simple grammar that is - in spite of its simplicity - extraordinarily well suited to program a knowledge base or expert system which then can be queried in an almost natural way. Moreover, a Prolog program can extend itself at runtime. It's therefore very easy to program a self-learning system with a hundred lines of code or so, that keeps adding knowledge every time you tell it something new.

Lisp and many other functional languages have similar concepts at their heart, but I'm not aware of any language that is as accessible and easy to learn as Prolog while still being as well suited to dabbling in expert-system-like AI.

P.S.:
Quick introduction to Prolog: Prolog | An Introduction - GeeksforGeeks[^]

nEar_mO wrote:

im using c# in creating artificial intelligence for my thesis, but i dont know where to start creating artificial intelligence...

WEll, looks like you choose your thesis topic poorly. Did you consider choosing something you had a clue on how to do ?

nEar_mO wrote:

it is possible that artificial intelligence can response on what user saying?...

That is the general idea.

nEar_mO wrote:

can you give me an idea on how to start it or any source code that can give me an idea

Copying source code and writing your thesis are opposing goals. Have you heard of Eliza ? If not, then you really know nothing about AI, making your choice of thesis even more ludicrous. It's a program that tries to parse what a user types and to turn it into a question, to create the illusion of conversation. You could google for source code of Eliza type programs.