I'm designing and developing a learning system based on flashcards and leitner system. The system have many features such as creating flashcards, studying the flashcards, doing tests and etc. The activity diagram of studying the cards is attached below. It goes through all decks of the box, studies the cards, which are due to be learned on that date and moves the cards accordingly weather the user answered the question correctly or not.
One of the options that the user has is to ask for a tip while the question is being asked. I showed it with a send- receive-signal but some of my team members believe that it's wrong.
Is my diagram regarding the send- and receive-signal correct? If not how can I show the option?