Answer:
B) irony, because he really does know where his brother is.
Step-by-step explanation:
Given that Irony is a term that describes a form of expression of an individual, whereby the intended meaning of such expression is the opposite of its literary meaning. It is often used amusingly or deflects meanings.
Also, given that the Bible revealed that Cain is the actual killer of Abel, who happened to be his brother.
Hence, it can be concluded that this is an example of "irony because he does know where his brother is."