In this step we will create all the actions needed in the workflow.

In the "Edit workflow" window select the "tasks" tab in the left hand bar. Drag the YesNo question and drop it on the transition arrow coming out of the start circle (the solid circle at the left of the workflow). Rename as required then click enter.

On to the top arrow (representing "yes"), drop a mail action from the "standard actions" tab. Drag another mail action on to the lower arrow (representing "no").

Connect the transitions coming out of the top mail action by dragging the end point of the arrow on to the end circle (the circle at the right of the diagram). Connect the lower arrow in the same manner. Your diagram should resemble the below.