The statement mentions that a large number of people affected by the flood gathered at the relief camp for food, water, and shelter. From this information, it can be inferred that the relief camp must have enough supplies to provide food and water to the affected people, which supports assumption I. Additionally, the statement also mentions that the relief camp is providing temporary shelters. Therefore, it can be assumed that all those whose houses are submerged can be accommodated in these shelters, which supports assumption II. However, there is no information in the statement to support assumption III, which states that many more affected people are yet to reach the relief camp. Therefore, the correct answer is "Only I and II are implicit."