Why Are Such a High Percentage of Infant Botulism Cases

Why are such a high percentage of infant botulism cases associated with ingestion of honey?

A) Bees cultivate C. botulinum bacteria within their hives as a food source, so it gets mixed in with the honey.
B) The infant digestive tract is far more susceptible to the effects of botulism toxin (found in the honey in relatively high levels) than the adult digestive tract.
C) The spores of C. botulinum produce a strong endotoxin. This endotoxin has little effect on adults due to their overall size. Infants, however, are significantly smaller (and therefore far more susceptible) than adults.
D) There can be endospores from C. botulinum in honey. They may germinate in the intestines of infants following consumption of honey, leading to colonization and pathogenesis as the bacteria begin forming botulism toxin. Adults' normal intestinal flora will outcompete the new microbes, but very young infants may not yet have this normal flora established.