(2) is out because ambiguous. P may not exist and the space may be a vacuum
(3) is out because ambiguous. Again from the picture, it is not clear if P and R is solid or liquid.
(4) is not because ambiguous. It may look like a liquid but it could be a solid, gelatin substance?
(1) is the clearest because it is upside down, yet the substance remains firm without flowing down. It could be a gelatin type of solid so it could stay up there. So it has its own volume fixed and does not move according to the container.