Answer: D Shellshock, also known as the Bash or Bashdoor vulnerability, was a major security flaw discovered in September 2014. It affected the Bash shell, which is commonly found in Unix-based operating systems, such as Linux, Unix, and OS X (now macOS). Windows, on the other hand, does not use the Bash shell by default and was not directly affected by the Shellshock vulnerability.

https://www.techtarget.com/searchsecurity/definition/Shellshock "Shellshock is the common name for a coding vulnerability found in the Bash shell user interface that affects Unix-based operating systems, including Linux and Mac OS X, and allows attackers to remotely gain complete control of a system." It doesn't affect Windows therefore D

correct, Windows is the correct option

Mac OS X (now known as macOS) is built on an open-source Unix-like operating system kernel known as Darwin. It is able to run Bash shell, hence vulnerable to Shellshock.

the thing is OS X is an apple OS, do not think apple use SSL though, why not OS X instead?

Shellshock is a bug in Bash so i would say Linux or Unix but not Windows