Which one of following would not be considered as a form of secondary device?

Which one of following would not be considered as a form of secondary device?

مندرجہ ذیل میں سے کس کو ثانوی ڈیوائس کی شکل نہیں سمجھا جائے گا؟
Explanation

R.A.M is not an example of a secondary storage device.

Secondary storage is a memory that is stored external to the computer.

It is mainly used for the permanent and long-term storage of programs and data.