What does informative enzyme selection mean in a restriction-digestion experiment?

Correct answer: Choosing enzymes that distinguish the correct construct from an incorrect construct

Informative enzyme selection means choosing restriction enzymes whose cutting pattern gives distinguishable results for alternative DNA constructs. For example, an enzyme may cut an insert-containing plasmid into two fragments, whereas an empty vector may remain as one fragment or produce fragments of different sizes. After electrophoresis, these predicted band patterns help identify the correct clone. Option A is correct because the enzyme is selected for its diagnostic value, not merely because it can cut DNA. Options B, C, and D describe unrelated properties: restriction enzymes do not signal their action by smell, do not directly manufacture proteins, and do not turn the reaction into water. The prediction should be made before digestion and compared with the observed gel pattern.