What does a compiler do?

A compiler is a specialized program that translates high-level programming code, which is generally more understandable to humans, into machine code that a computer’s processor can execute. This process is crucial because computers inherently operate using binary language, and the compiler acts as a bridge between high-level programming languages (like Python, Java, or C++) and the machine code specific to the computer's architecture.

The correct answer reflects the core functionality of a compiler, allowing developers to write in a more accessible language while ensuring that their code can ultimately be processed effectively by a computer. This translation occurs through several stages, including lexical analysis and syntax analysis, ultimately producing machine code or intermediate code that can be executed by the hardware or further optimized.

In contrast, the other responses misconstrue the role and operation of a compiler: for example, running code line by line is the function of an interpreter, whereas transforming code into its source format does not capture the essence of what a compiler does. Furthermore, while debugging is an essential aspect of the programming lifecycle, it is primarily the job of separate debugging tools rather than the compiler itself.