Which are valid c# name

Answer 1

Variables, method and class names, and other identifiers can only contain uppercase/lowercase letters, numbers, and underscores.
They cannot contain spaces, or symbols besides underscores. Keywords cannot be used as names (Ex: int, class, for, etc.)
They must start with a letter or underscore, and can't start with a number. Starting with an underscore is not recommended.

Exs: firstName, num2, input_word, GetAns()

Answer 2

thanks