What did G. J. Whitehurst's researchon reading to toddlers demonstrate?

a. Reading to children in any fashion resulted in the same outcomes.
b. Dialogic reading helped children gain more vocabulary than typical reading.
c. Dialogic reading can hinder a child's natural ability to learn to read.
d. Toddlers can make vocabulary gains by looking at picture books.

b. Dialogic reading helped children gainmore vocabulary than typical reading.