ANS:D - A program which translates source program into object program

We are written instruction in higher level language, while we use programming language like c, c++, java, .Net, COBOL all these languages are high level languages. While we are writing any instruction using these language that are written in high level language means user understandable language. But these instruction that device can not understand, so for that we use compiler, interpreter & assembler. All these are the translators.