Although many organisms (including eukaryotes) use the Embden-Meyerhof-Parnas (EMP) pathway for the initial catabolism of glucose, alternative glycolytic pathways do exist and are widespread among the prokaryotes. The Entner-Doudoroff (ED) pathway, for example, is widely used among Gram-negative bacteria (including E. coli) and archaea. Because the EMP generates slightly more energy, it has been considered the "better" and "more evolved" of the two. But is this assumption naive?

Of the following, which phenotype would most likely be observed in mutants of E. coli lacking a key enzyme in the ED pathway?

A. loss of ability to grow anaerobically
B. lack of flagellar motility
C. reduced ability to colonize the mammalian gut
D. inability to form biofilms
E. increased virulence