In which kingdom would be an immovable, multicellular, eukaryotic , autotroph belong

The answer is Plantae kingdom. The mentioned characteristics best describe the Kingdom. The next probable group would have been the Protoctista Kingdom but some move by use of flagella and cilia (hence not immovable). Protoctista Kingdom has heterotrophs too. The other known Kingdoms are Animalia, Fungi, and Prokaryotae.

First, look at your choices and eliminate the ones that obviously don't fit.
So a mandible (jaw) and a pupil (one the eye) don't work
Out of the two left..
A sclera won't work since it of apart of the eye.
So you only have orbit left.
By definition, orbit is the answer you are looking for.

Hope this helped! :)