I would agree with a. It evaporates from the lake, condenses in the clouds until it is heavy/large enough to fall again where it turns into precipitation. So you were correct there:)
The water will first get heated due to solar radiations. Heating of water will cause the water to evaporate. Due to evaporation process, water will get converted into water vapours. Water vapours are light in weight and also have kinetic energy so they will rise above the water surface and reach the higher destinations in the atmosphere known as troposphere. When more water vapours get accumulated in the air as compared to what it can accomodate, it starts to change the state from vapour phase to liquid phase. This is known as condensation. It is responsible for formation of clouds. As soon as, more and more water vapours start to cool down to become water droplets, the cloud cannot bear the weight of water droplets anymore as a result of which water starts to fall as rain. This process is known as precipitation.
Both climate change and humans were responsible for the extinction of some large mammals, according to research that is the first of its kind to use genetic, archeological, and climatic data together to infer the population history of large Ice Age mammals.
Because the reason why airplane have closed windows is because we can't breathe in carbon dioxide when we go up. Of course there is oxygen just not a lot as we go up. Why would there be helium in the air? We would sound weird when we skydive.
