(A) - (II) "because" → Shows the reason for reading mystery novels.
(B) - (III) "where" → Refers to the place of birth.
(C) - (IV) "since" → Indicates time passage from a past event.
(D) - (I) "unless" → Creates a conditional statement (if not).
Hence, Option 2: (A) - (II), (B) - (III), (C) - (IV), (D) - (I) → Each word correctly completes its sentence with proper grammatical function: "because" for cause/reason, "where" for place reference, "since" for temporal connection, and "unless" for negative condition → correct