At age 24 months, Avery was diagnosed with autism. Although his parents saw evidence of this earlier, as he did not engage in normal social behaviors, what new skill probably did not develop in toddlerhood that has doctors waiting for a diagnosis

a. Avery did not make eye contact with adults at age 2.
b. Avery did not toilet train at age 2.
c. Avery did not develop language skills at age 2.
d. Avery did not point to objects at age 2.

C. The diagnosis is usually made at 18-24 months when children should be verbal and are not.