Which one of the following is not a keyword in Python language?

Answer: Option B

In Python, keywords are reserved identifiers that have special meanings and purposes within the language.
eval is not a keyword in Python; rather, it is a built-in function used to evaluate a Python expression stored in a string.
Keywords like pass, assert, and nonlocal have specific meanings in Python and are reserved for special purposes within the language.
Therefore, the correct option is Option B: eval.