How did volcanic activity help in Earth's evolution?

Correct answer: By releasing gases to form atmosphere

The direct answer is A: volcanic activity helped form the atmosphere by releasing gases. In early Earth, volcanic eruptions brought gases from the interior to the surface. These gases included water vapour, carbon dioxide, nitrogen and other substances. As Earth cooled, water vapour condensed and contributed to oceans, while the remaining gases helped create the early atmosphere. Later changes, including the development of life, altered atmospheric composition further. Option A is correct because volcanism is an important source of gases during planetary development. Option B is wrong because volcanic activity did not make the Sun smaller; the Sun is a separate star governed by its own processes. Option C is wrong because volcanoes did not make oceans salt-free; salts come from dissolved minerals and other processes. Option D is wrong because eruptions do not end gravity; gravity is a fundamental force that continues to hold Earth together. The chain to remember is: eruption, gases, cooling and condensation, atmosphere and oceans. Exam cue: connect volcanoes with degassing and atmospheric formation.