Following a 14-day course of broad-spectrum antibiotics for the treatment of sepsis, a 60-year-old ...

Following a 14-day course of broad-spectrum antibiotics for the treatment of sepsis, a 60-year-old woman has developed watery diarrhea.
 
  Her care team attributes this to likely elimination of normal intestinal flora by the antibiotics. What other phenomena is most likely accompanying her low levels of normal flora?
  A)
  Decreased mineral and nutrient absorption; decreased carbohydrate metabolism
  B)
  Decreased pH of the stomach; increased pH of the lower GI tract
  C)
  Decreased fermentation of undigestible dietary residue; decreased vitamin absorption
  D)
  Proliferation of vitamin K; lower GI bleeding