Android : activity diagram in uml regarding parallel activities

I had a doubt regarding parallel activities that occur in the system. How can we represent those in the diagram? Is there always a need of fork or the decision element can also be used? Eg.: The user can choose among "Add Book" , "Search Book", "Search User" and "Update profile". So after the user logs in the system he can choose among the above operations. Below is the image of my activity diagram.