breaking external references

Hello,

I am unable to break my external references (make the part independent).

The options “List External References”, “Break Reference”, or “Lock” are not displayed for me in SolidWorks 2016.

“Tools → Options → External References” is also not shown.

What other options are there to remove external references of a part within an assembly, so that, for example, I can transfer external elements from another assembly while in sketch mode?

Thank you.