Which sentence from the passage contains the central idea?
Read the passage from "Zero-Gravity Nutrition."
It has long been a challenge to decide on astronauts'
food. Astronauts don't have the choice of foods that
are on Earth. In early space travel, the solution was to
put food in tubes. Tubed food probably sounds
strange to you! Today, foods are chosen to travel and
keep. For example, foods such as nuts and dried fruit
can be eaten in space just as they are.
o It has long been a challenge to decide on
astronauts' food.
O Astronauts don't have the choice of foods that are
on Earth.
O Tubed food probably sounds strange to you!
O Today, foods are chosen to travel and keep.