Step 1: Understand this match-list question.
This question shows the matching in an image, so the options and lists are inside the figure. We treat it as a subjective match of amino acids in List-I to their side chains $R$ in List-II.
Step 2: Recall what to match.
Each amino acid has the same backbone but a different side chain $R$. We identify the correct $R$ group for each named amino acid.
Step 3: Match alanine.
Alanine has the simple methyl side chain $R = -CH_3$. So alanine pairs with the methyl option, that is $A \rightarrow III$.
Step 4: Match leucine and serine.
Leucine has the branched side chain $R = -CH_2CH(CH_3)_2$, so $B \rightarrow I$. Serine has the hydroxyl side chain $R = -CH_2OH$, so $C \rightarrow II$.
Step 5: Match cysteine.
Cysteine has the sulphur-containing side chain $R = -CH_2SH$, so $D \rightarrow IV$.
Step 6: State the full matching.
Putting it all together, the correct combination is \[ \boxed{A-III,\ B-I,\ C-II,\ D-IV} \]
