Which reaction is most likely catabolic? a + b mc020-1.jpg c + energy a + b + energy mc020-2.jpg c a + energy mc020-3.jpg b + c a mc020-4.jpg b + c + energy

Catabolic reactions are reactions that break larger molecules down into smaller molecules, and often result in the release of energy as a by product of the bonds being broken. In fact, metabolism (the breakdown of food) is a catabolic reaction.

So the best answer would be the Answer no.4:
A => B + C + Energy

Digestion because it removes waste