When a playwright refers to something not explained within the play itself, like a myth or the Bible, he is using: dramatic irony. an aside. an allusion. a soliloquy.

He is using an allusion.

Explanation:

An allusion is a reference to something that is not mentioned or stated within the play itself, and it is usually something that the intended audience would have had knowledge of. It is used to make a comparison or draw a certain kind of attention to a specific point in the play.

it is the nurture that decides the behavior of a child.

explanation:

naturally, children are pure. it is an environment and the type of attention a child gets that determines their behavior.  

bildungsroman describes a coming-of-age story.

hope this you ; )