it is b because you see take a ruler and measure it
C. Permafrost
Permafrost is the layer beneath the "active layer". The active layer consists of soil that freezes and thaws every year. However, the requirement for permafrost is that it be frozen for two or more years consecutively. This is why permafrost exists in cold environments such as tundras.
Increase in urbanization will lead to increase in the number of people who are living in an urban area and it will also lead to increase in development in that area. The increase in development can come in form of construction of industries, which release large amount of waste products that pollute the air. This will lead to air pollution and reduce air quality. Development can also be in form of availability of electricity, that makes it possible for people to operate different electrical gadgets such as radio and television, which can result in noise pollution. Increase in the number of people who operate motor vehicles will also lead to increase in air pollution, which is caused by fossils fuel.
The main difference is that mitosis occurs in body cells and meiosis occurs in sex cells. Mitosis produces identical daughter cells and meiosis produces genetically different daughter cells.