Judge the following sentence according to the criteria given below: River runoff does mixes well with seawater along the coast BECAUSE freshwater is more dense than seawater. Option A The assertion and the reason are both correct, and the reason is valid. Option B The assertion and the reason are both correct, but the reason is invalid. Option C The assertion is correct, but the reason is incorrect. Option D The assertion is incorrect, but the reason is correct. Option E Both the assertion and the reason are incorrect.