It depends upon the launch mode of either B and D.

let's take the previous example: A →B → C →D

If only B has a SingleTask and D is Standard
Calling B then A →B will be a current state
or calling D then A →B → C →D →D

let's take D as SingleTask and B as Standard
A →B →C →D

Calling B then A →B → C →D →B will be a current state
or calling D then A →B → C →D onNewIntent of D will be called in this case.