Plants is to Coal as Animals is to ?

• A. Crops : Manure
• B. Animals : Oil
• C. Cow : Milk
• D. Fire : Smoke

Answer: (B)

The idea being tested is how a product is formed from its original organic source over a long, transformative process. Coal forms from ancient plant matter through heat and pressure over geological time. In the same kind of relationship, oil is formed from ancient organic material, including animals, through similar deep-time chemical changes. So the match is Animals to Oil because oil is the fossil-fuel product associated with animal-derived matter.

Other options don’t fit the same pattern: crops turning into manure would switch the source and product inappropriately, since manure comes from animals, not crops; cow turning into milk is a direct modern product of an animal rather than a long-term transformative product; fire producing smoke is a byproduct of combustion, not a long-term transformation of organic matter into a fossil fuel.