Read the paragraph below from the section "What practical factors did you consider when thinking about food production on Mars?" Mars has almost no atmosphere. The atmosphere is the layer of gases surrounding the planet. The atmosphere of Mars is much thinner than Earth's atmosphere. Mars is also very cold.

What conclusion can the reader make based on this paragraph?

(A) Conditions are much harsher on Mars than on Earth.
(B) People will be unable to grow their own food on Mars.
(C) Structures on Mars will be bigger than structures on Earth.
(D) There is a limited amount of land to use to grow food on Mars.