Which of the following translates a complete high-level language program into machine code?

The choice of a compiler is correct because a compiler is a program that translates the entire high-level programming language code into machine code in one go. This process involves several stages, including lexical analysis, syntax analysis, semantic analysis, optimization, and code generation. The end result is typically an executable file that the machine can run directly, which offers advantages in terms of performance since the entire program is translated before execution.

Compilers work by taking source code written in languages like C, C++, or Java, and converting it into machine code that the computer's processor understands. This process also allows for various optimizations to improve the program's performance.

Other options represent different processes in the realm of programming. An interpreter translates high-level code into machine code but does so line-by-line at runtime, which means it executes the code directly without creating a standalone executable. An assembler, on the other hand, translates assembly language into machine code, which is a low-level language closer to binary than high-level programming languages. Lastly, a linker is used after compilation to combine different object files into a single executable, resolving references among them but does not translate high-level language programs directly into machine code.