Which programming transformation method translates high-level language to machine language all at once?

The method that translates high-level language to machine language all at once is compilation. In the compilation process, the entire program is converted from a high-level language, such as Python or Java, into machine code or intermediary code that the machine can understand and execute directly.

This transformation occurs before the program runs, resulting in a standalone executable file that can be executed multiple times without the need for re-translation. The advantage of compilation is that once the program is compiled, it can often run faster since it does not require on-the-fly translation during execution.

In contrast, interpretation translates and executes code line by line, meaning that it does not produce a standalone executable file and can be slower in execution. Execution refers to the actual running of the program rather than the transformation of code, and translation is a more general term that doesn't specifically indicate the method of transformation used. Therefore, the focus on the compilation method clearly distinguishes it as the correct choice for translating the entire high-level language to machine language at once.