ANSWER
Option a.
Step-by-step explanation
We have the hanger in the diagram.
On the left there is a square and a triangle and on the right there are two circles and a triangle.
The hangar will be in balance when the number of shapes on both sides are the same.
So, for the hangar to be in balance, two circles need to be added to the left side and one square needs to be added to the right side.
So, the correct option is a)