Ficus often drop leaves when humidity is lowered. Try locating your tree outside on your patio where humidity will be high and you can still enjoy your tree. It will do much better in an outside environment. A. Ming aralias can be grown as a houseplant but are quite temperamental about watering schedules and very subject to spider mites. Ming aralias like humidity, but want to be kept on the dry side.
Air conditioning is also a strain on the plant.
I would plant it outside and enjoy it. Locate the plant so it gets morning sun if possible. If you leave it in the pot, make sure that it doesn't dry out excessively. Q. My fern fronds are turning brown and dropping off. I think they are dying.