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IBM Quantitative Aptitude Core Computer Science Medium

Which one of the following is NOT a reserved keyword in the C programming language?

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Which one of the following is NOT a reserved keyword in the C programming language?

Choose one option.
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Answer: B. inc

volatile, sizeof, and default are all reserved keywords in C. volatile is a type qualifier, sizeof is a unary operator, and default is used in switch statements. inc is not a reserved keyword—it is a valid identifier that can be used for variable or function names.

Step-by-step Derivation:
Review C reserved keywords: (1) volatile — type qualifier for preventing compiler optimization. (2) sizeof — unary operator to get size of types/variables. (3) default — label in switch statements. (4) inc — NOT in the C standard reserved keyword list; commonly used as a variable/function name (e.g., inc(), inc_value). Therefore, inc is the correct answer.