The correct answer is C. glass vessel.
Sulphuric acid is a strong acid that can react with many metals, including copper and aluminium. Glass is a non-metallic material that is not reactive with sulphuric acid. Therefore, a glass vessel is the most suitable vessel for storing concentrated sulphuric acid.
A copper vessel would react with the sulphuric acid to form copper sulphate and hydrogen gas. This reaction is exothermic, meaning that it releases heat. The heat generated by the reaction could cause the copper vessel to melt.
An aluminium vessel would also react with the sulphuric acid to form aluminium sulphate and hydrogen gas. This reaction is also exothermic. In addition, aluminium is a relatively soft metal, so it could be easily corroded by the sulphuric acid.
An earthen vessel is made of clay. Clay is a porous material, so it could absorb the sulphuric acid. This would cause the vessel to break down over time.
Therefore, a glass vessel is the most suitable vessel for storing concentrated sulphuric acid.