**Interpreters**

An interpreter is a type of translator that converts a program line-by-line to machine language while executing it. It reads and executes the source code directly, without the need for an intermediate compiled version. Here's a detailed explanation of why the correct answer is option 'C':

**1. Assemblers:**
Assemblers are a type of translator that converts assembly language code into machine language. Assembly language is a low-level programming language that uses mnemonic instructions and symbols to represent machine code instructions. Assemblers are not capable of converting high-level programming languages into machine language.

**2. Compilers:**
Compilers are a type of translator that converts the entire source code of a program into machine language all at once. It goes through multiple phases, including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation. The output of a compiler is a standalone executable file that can be directly executed by the computer's operating system.

**3. Interpreters:**
Interpreters, on the other hand, work by executing the source code line-by-line. It reads each line of code, converts it into machine language, and immediately executes it. This process is repeated until the entire program is executed. Interpreters are commonly used for scripting languages like Python, JavaScript, and PHP. They provide a more interactive development environment as errors can be caught and corrected immediately during execution.

**Advantages of Interpreters:**
- Interpreters are generally easier to learn and use compared to compilers.
- They provide a more interactive development environment, allowing for quick code testing and debugging.
- Changes to the source code can be immediately seen and tested without the need for recompilation.
- Interpreters are often platform-independent, running on multiple operating systems without the need for recompilation.

**Disadvantages of Interpreters:**
- Interpreted programs tend to be slower in execution compared to compiled programs. This is because each line of code is translated and executed on the fly.
- Interpreters require the interpreter software to be installed on the target system to run the program. This can be a limitation when distributing software to users.

In conclusion, interpreters are a type of translator that converts a program line-by-line to machine language while executing it. They provide an interactive development environment but may have performance limitations compared to compiled programs.