Answer:
Option (B)
Step-by-step explanation:
The oxygen isotope ratios are often used from water that are stored in the glaciers and the oxygen that are absorbed in the shells of the marine flora and fauna. This ratio is used to determine the past climate and rainfall.
The data obtained by calculating this ratios demarcates that the changes in the climatic condition definitely affects the changes in the life forms. If organisms existing in a warm climate are suddenly allowed to experience a colder type of climate, then these organisms have to adapt to that environment for their survival. Due to this adaptation, the organisms undergo certain changes in them, thereby undergoing the process of evolution.
Thus, changes in the life form occurs due to the changing environmental and climatic conditions.
Hence, the correct answer is option (B).