C. FLOOD STAGE is reached when the water level of a stream or river exceeds its natural banks.
Flood stage is a level at which a body of water's surface has risen to a sufficient level to cause sufficient inundation in areas that are not normally covered by water, causing inconvenience or a threat to life and/or property.
C. Melting ice.
It is C because melting ice is a change of state from solid to liquid which requires an addition of energy(or entropy) into the system.
Condensation of water occurs from a gas to a liquid state, which takes energy out of the system(water) and gives it to the surroundings(air around it). Freezing water is the same as condensation except for the state change. Deposition is simply gas to a solid instantaneously so you can again see it as with the other two examples.
Answer : The molarity and molality of the solution is, 18.29 mole/L and 499.59 mole/Kg respectively.
Solution : Given,
Density of solution = 
Molar mass of sulfuric acid (solute) = 98.079 g/mole
98.0 % sulfuric acid by mass means that 98.0 gram of sulfuric acid is present in 100 g of solution.
Mass of sulfuric acid (solute) = 98.0 g
Mass of solution = 100 g
Mass of solvent = Mass of solution - Mass of solute = 100 - 98.0 = 2 g
First we have to calculate the volume of solution.

Now we have to calculate the molarity of solution.

Now we have to calculate the molality of the solution.

Therefore, the molarity and molality of the solution is, 18.29 mole/L and 499.59 mole/Kg respectively.