In what file do you change default shell variables for all users?

A.
/etc/bashrc

B.
/etc/profile

C.
~/.bash_profile

D.
/etc/skel/.bashrc

E.
/etc/skel/.bash_profile

Explanation:
When invoked interactively with the –login option or when invoked as sh, Bash reads the /etc/profile instructions. These usually set the shell variables PATH, USER, MAIL, HOSTNAME and HISTSIZE. All settings that you want to apply to all your users’ environments should be in this file.