Step 1: Concept Assessment: This question evaluates understanding of pack animal adaptations and their transportation utility across diverse geographical areas.
Step 2: Detailed Analysis: Matching animals from List-I with their respective regions from List-II:
(A) Mules: Renowned for strength and sure-footedness, mules are suited for heavy loads in rugged, steep terrains. Thus, they are commonly used in (I) Mountains.
(B) Camels: Referred to as "ships of the desert," camels are exceptionally adapted to arid environments with minimal water, serving as the primary transport in (III) Deserts.
(C) Reindeer: Adapted to cold, snowy climates, these animals are utilized by indigenous populations in Arctic and sub-arctic regions, such as (II) Siberia, for pulling sleds.
(D) Horses: While globally employed, horses have historically been a significant mode of transport and labor in (IV) Western Countries and continue to serve various functions.
The correct pairings are: A$\rightarrow$I, B$\rightarrow$III, C$\rightarrow$II, D$\rightarrow$IV.
Step 3: Conclusion: Based on the established pairings, option (2) presents the accurate combination of animals and their associated regions of use.