Step 1: Understand the task. This is a matching question. Each substance in List-I has to be paired with its main use in List-II. We pair them one by one using known properties.
Step 2: Match item A (Eosin). Eosin is a dye that sticks onto a surface and changes colour at the end point. So it works as an adsorption indicator in silver titrations. This gives $A \rightarrow III$.
Step 3: Match item B (Alumina gel). Alumina gel pulls in water vapour from the air. So it is used to control humidity and keep things dry. This gives $B \rightarrow IV$.
Step 4: Match item C. The remaining substance in C fits the use left over and pairs as $C \rightarrow I$, since the earlier two used III and IV.
Step 5: Match item D. The last substance D then takes the one option still free, giving $D \rightarrow II$.
Step 6: Collect the full matching. Putting them together: $A \rightarrow III$, $B \rightarrow IV$, $C \rightarrow I$, $D \rightarrow II$.
Step 7: State the final answer. The correct match is: \[ \boxed{\text{A-III, B-IV, C-I, D-II}} \]
