Holden begins talking to his dead brother, Allie.
A, because it is in order of how to boil water
This is an example of parallelism.
Parallelism is repeating grammatical constructions in the same way.
For example, the statement: "I came, I saw, I conquered" is parallel because each segment is NOUN + VERB (past tense). If it were written: I came, I saw, I was conquering" then the statement would not be parallel.
Answer:
the purpose of our life is to be happy