Of the four basic elements of classical conditioning, the one the organism learns to respond to is the:

Teratogens usually affect a wide range of body systems

Indicate whether the statement is true or false

The diagnosis of Attention-Deficit/Hyperactivity Disorder requires that at least some hyperactive or inattentive symptoms must have been observed before what age?

a) 3 b) 5 c) 7 d) 15