Oxford, Cambridge and RSA (OCR) GCSE Computer Science Practice Exam

Machine code is the correct answer as it is the lowest level of programming language, consisting entirely of binary digits—1s and 0s. This binary format is directly understood by a computer's central processing unit (CPU), which executes instructions in this form without needing translation or interpretation. Each instruction in machine code corresponds to specific operations the processor can perform, such as arithmetic calculations or data manipulation.

In contrast, high-level code consists of coding languages like Python or Java, which are designed to be easily readable by humans but require translation into machine code for the computer to execute. Assembly language is a step above machine code; it uses mnemonics and symbols to represent machine-level instructions, making it more manageable for programming than pure binary but still closely tied to the architecture of the hardware. Scripting languages, like JavaScript or Ruby, are designed for automating tasks and are interpreted at runtime rather than being compiled into machine code. These options illustrate the various layers of abstraction in programming languages, with machine code firmly at the base, providing the fundamental instructions that a computer can directly execute.