Outgassing helped in the development of what on Earth?

Correct answer: The early atmosphere

Outgassing is the release of gases from Earth’s hot interior through volcanic activity and related processes. During the early history of the planet, water vapour, carbon dioxide, nitrogen and smaller amounts of other gases were released and gradually contributed to the formation of a primitive atmosphere. Later, cooling and condensation allowed water to collect, while biological processes changed the atmospheric composition further. Option A is therefore correct because outgassing supplied much of the material for the early atmosphere. A galactic arm belongs to the structure of a galaxy, the solar core is part of the Sun, and cosmic red shift is an observational effect caused by the motion or expansion of space; none of these is formed by terrestrial outgassing.