This .NET interview question is mainly asked to test if you have used coding standards in your project. All the above three are naming conventions which are followed in programming languages to ensure a proper and neat code. Below is the explanation of each naming convention.
Pascal Notation- In this naming convention all starting letter of the words are in Upper Case and other characters are lower case.
Camel Notation- In this naming convention first character of all words, except the first word are Upper Case and other characters are lower case.
Hungarian notation - In this naming convention the variable name starts with group of small letter which indicate data type.