"history" option for "router.navigate" method

When I set “history” option for “router.navigate” method to “false” which page will not save in the history? Previous page, current page or target page?

There are links between pages like this:
A to B to C

In C page there is a “Save” button. When user click it, programatically route to B. If user click back button in B page, I don’t want C page to open. I want A page to open.