Explanation:

Machine language is the fundamental language that a computer's central processing unit (CPU) directly executes. Every computer architecture, regardless of its manufacturer or operating system, has its own specific machine language (instruction set) that is universally understood by all processors of that type. While the exact instruction set varies between architectures (e.g., $\text{x86}$, $\text{ARM}$), the *concept* of machine language as the directly executable code is applicable to all computers. High-level languages require specific compilers/interpreters for each platform. (a) Basic language: Incorrect. BASIC requires an interpreter or compiler, which may not be available on all systems. (b) Cobol language: Incorrect. COBOL also needs a specific compiler and runtime environment. (c) Machine language: Correct. Every computer executes instructions in its native machine language. (d) Fortran: Incorrect. Fortran, like other high-level languages, needs a compiler for specific platforms. (e) None of these: Incorrect, as (c) is the correct answer.