Believing that sunshine and fresh air will make children ill, the natives in one Guatemalan village isolate their children until they are 13 to 14 months of age (Kagan & Klein, 1973). After this isolation, the children

a. remain apathetic.
b. are physically and mentally retarded through adulthood.
c. are as intellectually and physically able as American children by age 11.
d. regress even further in their physical and emotional development.

c