What is the correct conduct?

You selected that you let the tram through, which is correct.

In this situation, trams always have priority over other vehicles unless there are specific signals or signs stating otherwise. Even though you are on a priority road (shown by the yellow diamond), the tram coming from the left must be allowed to go first. The tractor, however, must wait because it is joining from a side street and does not have priority.

Remember: In most intersections, trams have special right of way, even over vehicles on a priority road. This helps keep trams running on schedule. Always check for trams before proceeding, even if you appear to have priority by road sign.