Step 1: Recall what each list covers.
The Union List has subjects only the central government handles, like defence and foreign affairs. The State List has local subjects like police. The Concurrent List has subjects both can legislate on, like adoption and marriage. Anything left out, like new subjects such as computer software, falls under residuary powers with the centre.
Step 2: Match each item directly.
Defence goes with the Union List (a to iv), Police goes with the State List (b to i), Adoption goes with the Concurrent List (c to iii), and Computer Software, being a modern subject not listed anywhere originally, goes under Residuary (d to ii).
Step 3: Check against the options.
This combination a-iv, b-i, c-iii, d-ii matches option (C) exactly, so there is no ambiguity in the pairing.
Step 4: State the final answer.
Hence, the correct answer is option (C): a-iv, b-i, c-iii, d-ii.