The diagram illustrates a straightforward metabolic pathway. $W \rightarrow X \rightarrow Y \rightarrow Z$ The letters W, X, Y and Z stand for four different substances. At every stage in the diagram, the substrate is changed in a chemical reaction that is catalysed by an enzyme. This reaction forms the next substance in the pathway. Which statements accurately describe the enzymes involved in this metabolic pathway?
- A1, 2 and 3
- B1 and 2 only
- C1 and 3 only
- D2 only