Option 1. Only assumption I is implicit. The statement shares that Earthquakes occur when underground layers of Earth shift suddenly and Earth shakes violently. From what is supplied it can be assumed that Earthquakes cannot be predicted. This assumption is validated by the use of the adverb "suddenly". Hence, assumption I is implicit. But, from what is given the intensity of damage and its inevitability cannot be assumed. Therefore, assumption II is not implicit. Hence, option 1 is correct.