How can new commands be taught to Karel?

Teaching new commands to Karel involves defining a new function. In Karel programming, functions serve as reusable blocks of code that can encapsulate specific behaviors. This allows a programmer to create complex behavior by combining simpler commands into a single function that Karel can execute whenever that function is called.

When you define a new function, you are essentially creating a custom command for Karel that abstracts away specific instructions. This improves code organization and readability, making it easier to manage the program and encouraging code reuse. For example, if you wanted Karel to perform a specific sequence of moves or actions multiple times throughout your program, you would define that sequence as a function and then simply call that function whenever needed.

The other choices do not facilitate the teaching of new commands effectively. Built-in functions offer predefined functionality but do not allow for the creation of custom commands. Creating a new variable is more about data storage and manipulation and does not directly relate to command creation. Writing comments is useful for documentation and clarification within the code but does not alter Karel's ability to execute new commands.