What is the right course of action?

You answered correctly by choosing to only turn after the motorcycle and before the yellow car. Here’s why: You are on the priority road (shown by the yellow diamond sign), so you have priority over the yellow car, which must yield when turning left. However, the oncoming motorcycle going straight has the right of way over your left turn. The correct order is: let the motorcycle go first, then you turn, and then the yellow car can turn. Remember, when turning left on a priority road, yield to oncoming traffic going straight, but oncoming left-turners must wait for you. This is the general rule at intersections with this priority situation.