What happens to weight when the temperature of water increases?

Answer: B — Weight decreases

When the temperature of water increases, the weight of the water itself remains constant, as weight is a measure of mass under the influence of gravity, and the mass of the water does not change with temperature. However, what does change is the density of the water. As water is heated, it expands, which means that for a given volume, the mass is still there, but the density decreases. This effect can lead to the perception that weight changes if you were to measure a volume of water, but in reality, the weight does not decrease. Thus, the correct assessment is that the weight does not change; it remains the same regardless of temperature variations.