Why does Bruno pretend that he has an imaginary friend?

Practice
A
He accidentally tells Gretel about Shmuel and fears she will ruin their friendship.

B
Due to the heavy rain, he can't visit Shmuel and is feeling lonely.

C
He regrets not comforting Shmuel, so he creates an imaginary friend to practice talking to.

D
Since Shmuel is angry with Bruno, he creates an imaginary friend to take his place.