Explanation:

Both A are R is true and R is not the correct explanation of A

• The air temperature begins to rise into the stratosphere. Such a temperature increasing prevents much air convection beyond the tropopause, and therefore most weather phenomena, including bearing clouds of thunderstorms, cumulonimbus, are confined to the troposphere.
• The main reason why most of the weather takes place in the troposphere is because it is next to the surface, hence next to the most important supply for weather processes, the water vapor that comes from the oceans. Weather takes an energy supply to happen, and the oceans provide that in abundance.