The correct answer is option 4: Compiler. A compiler is a type of program that converts high-level programming languages, such as C, C++, Java, or Python, into machine language or binary code that can be understood and executed by a computer. This process is known as compilation.

Let`s discuss the other options to have a better understanding:

Option 1: Linker. A linker is a program that takes object files, which are the result of compiling source code, and combines them to create an executable program or library. It resolves the references between different object files and creates the final executable.

Option 2: Assembler. An assembler is a program that converts assembly language code, which is a low-level programming language specific to a particular computer architecture, into machine language. It translates mnemonic instructions into their binary representation.

Option 3: Interpreter. An interpreter is a program that reads and executes high-level language code line by line, without the need for prior compilation. It translates and executes the code in real-time.

In summary, while all the options mentioned are important in software development, the correct answer for the program that converts high-level programming language to machine language is a Compiler.