What type of tool is an interpreter in relation to high-level programming languages?

An interpreter is a tool designed to convert high-level programming language code into machine code, but it operates by doing so one line at a time, rather than compiling the entire code at once. This means that when the code is run, the interpreter reads each line, converts it to machine-readable format, and then executes it immediately. This line-by-line execution allows for quicker testing and debugging since the programmer can see the output of each line as it is executed, making it easier to find errors.

In contrast, a compiler translates the entire program into machine code all at once, producing an executable file that can be run independently of the original source code. The option referring to machine code assembly typically describes an assembler, which works with low-level assembly language rather than high-level programming languages. Lastly, while some interpreters may execute high-level functions, this does not define their primary role, which is to interpret and execute code line by line.