I think it’s Igneous rock
I think that pressure will affect the solubility of gasses the most. The reason why I think this is that gasses are affected the most by pressure change. By definition solids and liquids are not easily affected by pressure by how close the molecules are to each other in both of those phases.
I hope this helps. Please let me know if you have any further questions or need any clarification.
I am probably wrong but I would think 900. I wouldn’t submit that without somebody backing me up though.
Push the pushbutton to the first stop before inserting the tip into the solution, and then put the tip in the solution tube.