Which answer figure will complete the pattern in the question figure?

As we can see that the given question figure is divided into triangles. Each of the triangles has one circle inside which is half-filled with black colour and the remaining is unfilled.

Now when we will observe the options, then there is a difference in the filling pattern of the circle. In the question figure, the circle is filled with three possible types and now only one type is remaining which is available in option (c). So the missing part of the given question figure can be filled by option (c) appropriately.