To determine which options are not keywords, we need to understand what keywords are in programming.
Keywords are predefined reserved words in a programming language that have special meanings and cannot be used as variable names or identifiers. These keywords are typically used to define the syntax and structure of the programming language.
Now, let's go through each option to determine which ones are not keywords:
Option A) (D) & (E) - This option includes (D) and (E) as not keywords. (D) is "extended" and (E) is "string". "extended" is not a keyword, but "string" is a keyword in many programming languages.
Option B) (A), (D) & (E) - This option includes (A), (D), and (E) as not keywords. We have already determined that (D) is not a keyword, and (A) is "NULL" which is also not a keyword. However, (E) is "string" which is a keyword.
Option C) (D) - This option includes (D) as not a keyword, which is correct.
Option D) (C), (D) & (E) - This option includes (C), (D), and (E) as not keywords. We have already determined that (D) is not a keyword. (C) is "protected" which is a keyword in many programming languages. (E) is "string" which is also a keyword.
Based on the above analysis, the correct answer is B. The options (A), (D), and (E) are not keywords.