Ali: I want to build a house on Mars one day.
Elif: That sounds amazing! But we need oxygen to breathe there.
Ali: Yes, scientists are working on making oxygen from the Martian soil.
Elif: So, maybe in the future, people can live on Mars.
According to the conversation above, what do we learn about Ali?
A)He fears living on Mars because of the oxygen problem.
B)He dreams of building a house on Mars.
C)He thinks that oxygen is already available on Mars.
D)He doubts whether scientists can create oxygen on Mars.