Shigella sonnei is the cause of an infection commonly seen in infant day-care facilities due to

A) a high prevalence of the microbe in young children.
B) its ability to contaminate and grow on plastic toys.
C) its inherent antimicrobial nature (it is bleach and cleaning-product resistant).
D) diaper changes and hands not being properly washed.
E) Gram-positive cell wall structure making the bacteria environmentally resistant.