Context: If he heard that we talk about anything going out , he will start to asking to go " tai tai ( going out ) " . He will be talking loudly and happily in his own language if I am driving him out in my car . Whenever I tried to hide from him and he could not find me , he would shout out loudly for " TU - TU ( auntie ) " .
Question What may be the reason that he talks in his own language ?
Possible answers:

(A). Because he is in the car .;
(B). Because he wants to go out .;
(C). Because he is a baby .;
(D). None of the above choices .;
The answer:
(C).