Final answer:
Common features among all programming languages include syntax, keywords, and operators, which are essential components of a language's structure and functionality.
Step-by-step explanation:
The question pertains to features that are common across various programming languages. Among the options listed, the correct answer is d. syntax, keywords, and operators. These are elements found in all programming languages, although their specific implementation details may differ between languages. Syntax refers to the rules that define the structure of code in a language. Keywords are reserved words with specific meanings and uses in the language, such as if, else, for, and while. Operators are symbols that perform operations on variables and values, like addition (+), subtraction (-), and multiplication (*).
Learning different programming languages such as Python, Java, or Perl involves understanding their unique syntax, keywords, and operators.
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