The following is missing for the question to be complete:
A) Vocal behaviour
B) Verbal behaviour
C) A & B
D) None of the above
Answer: Verbal behaviour
Explanation: Verbal behaviour is behaviour used by children like Anita, for example, where the meaning of a word is learned by function while the linguistic meaning of the word comes later, that is, later learned. This is when parents want to teach their child a word, they first teach the child the function of the word and then how the word is spoken in a language.
But to put it more precisely, verbal behaviour refers to when a child wants a specific pointing at something, a cracker, wants to satisfy a function if s / he is as hungry as Anita, rather than simply pointing out that there is a cracker on the counter.