In a Study by O'Neill and Gopnik (1991), 4- and 5-Year-Olds

In a study by O'Neill and Gopnik (1991) , 4- and 5-year-olds were able to correctly describe what was in a tunnel and how they knew what was there. Three-year-olds, however, were not as successful. How did the researchers know that the 3-year-olds did not understand the source of their knowledge?

A) The 3-year-olds could not identify what was in the tunnel.
B) Some children reported seeing things in the tunnel that were not there.
C) Some children identified a ball as blue after feeling it but not seeing it.
D) Many children identified a ball in the tunnel when there was no ball there.