Can operating system be made by any programming language?

Question

One day I was thinking that c# is used for Windows and c is used for Mac os, so just like that, os can be made by any programming language?

Answer 1

Operating systems are different from apps. You need to go a tad low-level.

https://www.quora.com/What-programming-language-are-operating-systems-written-in

Answer 2

No, creating an operating system requires access to the BIOS. Considering that java runs on a virtual machine it is impossible to gain access to the BIOS unless a cernal is already in place.

Probably all operating system is written in more than one language.
For example android runs on a linux kernal wich is written in c. The Libraries and Runtime is written in c++. And the applications and application framework is written in Java