Which statement does not explain, why many biochemical processes are carried out via multi-step pathways rather than by single-step reactions (or only a few steps)?

A. Multi-step pathways allow for more control points to regulate biochemical processes.
B. There is greater control over the amounts of energy that are consumed or released at any one time.
C. Sharing of intermediates between pathways is facilitated this way.
D. The end products of most pathways can usually be produced only by the pathway reactions that nature has evolved.